Showing posts from 2018

Martian methane—spotted in 2004—has mysteriously vanished. Source:   By Paul Voosen, Science Magazine. Excerpt: Scientists first detected traces of [methane]—a critical indicator of life on Earth—in the planet’s atmosphere decades ago. But today, researchers reported that a European satellite hasn’t spotted a single trace of methane. The finding, if it holds up, could complicate scientific dreams that martian microbes might be spewing the gas in the planet’s subsurface. ...scientists suspect that hundreds of tons of organic carbon pour into the martian atmosphere each year from solar system dust, reacting with solar radiation to form methane, say John Moores, a planetary scientist at York University in Toronto, Canada. “Where is all that carbon going?”...  

New Horizons flyby of Kuiper Belt object Ultima Thule (2014 MU69) Source:   NASA New Horizons is the superb spacecraft mounted with instruments that gave us all those rich, rich images and data in its flyby of Pluto in July of 2015.  Soon those exquisite instruments can be focused on yet another world in our Solar System, this time a Kuiper Belt object! Ultima is 100 times smaller than Pluto, but was likely formed 4.5 or 4.6 billion years ago, 4 billion miles from the Sun. It's been at near absolute zero temperature ever since, so it's likely the best sample of the ancient solar nebula ever studied. Will Ultima turn out to be a collection smaller bodies? Will it have an atmosphere? Will it have rings? Will it have moons? Any of that could be possible, and soon we'll know the answers to these questions. It flies by Ultima News Years Day — 2019 Jan 1. Get ready to wish New Year to New Horizons.

Megapixels: Watch NASA's OSIRIS-REx spacecraft zoom in on its asteroid target Source:   By Jillian Mock, Popular Science. Excerpt: On Monday, a NASA spacecraft reached the near-Earth asteroid Bennu, kicking off a research mission that could help us unlock secrets of the early solar system and, hopefully, the start of life on Earth. The spacecraft, named OSIRIS-REx (because Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer doesn’t exactly roll off the tongue), has been beaming pictures of its approach to the asteroid all the way, allowing us to get a really close look for the first time. ...After a two year journey traveling to reach the asteroid’s orbit between Earth and Mars, the spacecraft is now less than 12 miles from Bennu. Following a few initial passes to get a sense of spin, mass, and shape, OSIRIS-REx will drop in close enough to start orbiting the asteroid in its weak field of gravity. If this happens as planned in January 2019, Bennu will become the smallest

NASA’s InSight Mission Has Touched Down on Mars to Study the Red Planet’s Deep Secrets Source:   By Kenneth Chang, The New York Times. Excerpt: The InSight lander, NASA’s latest foray to the red planet, has landed. ...In the months ahead, InSight will begin its study of the Martian underworld, listening for tremors — marsquakes — and collect data that will be pieced together in a map of the interior of the red planet and help would help scientists understand how Mars and other rocky planets formed. ...“We can basically use Mars as a time machine to go back and look at what the Earth must have looked like a few tens of millions of years after it formed,” said Bruce Banerdt, the principal investigator of the mission. ... The main scientific part of the mission will not begin for a few months. ...InSight will use two main instruments: a dome-shape package containing seismometers and a heat probe that is to burrow about 16 feet down. ... Two identical spacecraft known as Mars Cube One, or MarCO for

How to Land on Mars Source:   By Jonathan Corum, The New York Times.

NASA’s next Mars rover will land in Jezero crater, which once hosted a lake and a river delta Source:   By Paul Voosen, Science Magazine. Excerpt: Update: NASA today announced the destination for its next Mars rover, due for launch in 2020. The agency said it would send the rover to the 50-kilometer-wide Jezero crater, which billions of years ago harbored a lake that half filled the 500-meter-deep basin. The crater also contains within its rim a fossilized river delta, the sediments from a river that spilled into the crater—a promising place to search for evidence of past life. [see photo in article; ] “Getting samples from this unique area will revolutionize how we think about Mars and its ability to harbor life,”  Thomas Zurbuchen, NASA’s associate administrator for science in Washington, D.C., said in a press con

Anything faster than a brisk walk on this martian moon could send you spinning off into space Source:    By Joshua Rapp Learn, Eos/AGU. Excerpt: Walk, don’t run, on the martian moon Phobos. A new study finds that traveling faster than about 5 kilometers per hour on some regions of the Red Planet’s largest satellite could shoot you straight off into space. Phobos... is an odd duck among our solar system’s moons. It’s tiny (a fraction of a percent the size of our own moon) and is shaped like a potato; that weird shape draws gravity to different places, depending on where you are. All these features make Phobos a challenge to travel on, researchers report in Advances in Space Research. In some places, moving any faster than 5 kilometers per hour would be enough to free you from the moon’s meager gravitational pull, sending you off into space.... The fastest you could travel anywhere on Phobos would be about 36 kilometers per hour, or a little faster than a golf cart, t

International Team, NASA Make Unexpected Discovery Under Greenland Ice Source:   NASA RELEASE 18-099. Excerpt: An international team of researchers, including a NASA glaciologist, has discovered a large meteorite impact crater hiding beneath more than a half-mile of ice in northwest Greenland. The crater — the first of any size found under the Greenland ice sheet — is one of the 25 largest impact craters on Earth, measuring roughly 1,000 feet deep and more than 19 miles in diameter, an area slightly larger than that inside Washington’s Capital Beltway....   See also 2019-02-12. Radar reveals a second potential impact crater under Greenland’s ice. By Paul Voosen, Science Magazine. [ ]

Super-Earth spied in the second-closest star system from the sun Source:   By Daniel Clery, Science Magazine. Excerpt: Our corner of the Milky Way is getting rather neighborly. In 2016, astronomers discovered a planet orbiting Proxima Centauri, the nearest star to our sun, just 4 light-years away. Now, they believe they have found an exoplanet around Barnard’s star, which at 6 light-years away is the second-closest star system. The planet—a chilly world more than three times heavier than Earth—is close enough that scientists could learn about its atmosphere with future giant telescopes. “This is going to be one of the best candidates,” says astronomer Nikku Madhusudhan of the University of Cambridge in the United Kingdom, who was not part of the discovery team. Barnard’s star b, as the new planet is called, was excruciatingly difficult to pin down, and the team is referring to it as a “candidate planet” though it is confident it’s there. ...Hundreds of exopl

Atacama Desert’s Unprecedented Rains Are Lethal to Microbes Source:   By Katherine Kornei, Eos/AGU. Excerpt: Chile’s Atacama Desert is the driest place on Earth. It receives just millimeters of rain each year, on average, and its parched conditions make it a commonly used stand-in for Mars. Last year, scientists working in the Atacama were astounded to find multiple lagoons of liquid water there—the ephemeral runoff from an unusual rain event. But the rainfall that created these ponds didn’t result in a bloom of life, the researchers found; it was actually lethal to the majority of microbes adapted to the extreme aridity of the Atacama. These findings have implications for future spacecraft missions that will collect samples from other planets: Incubating dry soil samples in aqueous solutions, as was done with the Viking landers on Mars in the 1970s, may have the inadvertent effect of killing microbial life. ...Azua-Bustos and his team hypothesized that the

After visits with Vesta and Ceres, asteroid-exploring Dawn spacecraft goes dark Source:   By Paul Voosen, Science Magazine. Excerpt: ...After several missed attempts to communicate with Dawn over the past 2 days, NASA declared that the spacecraft had run out of hydrazine and reached the end of its mission. ...[original coverage from 17 October]: ...After an 11-year journey to Vesta and Ceres, the asteroid belt's two largest members, NASA's Dawn spacecraft ... gave a close-up view of how the presence or absence of water can shape asteroids, will remain tumbling in orbit around Ceres for decades before ultimately crashing into it. Launched in 2007, Dawn is the only NASA mission to orbit two planetary bodies, a feat made possible by its efficient ion thrusters. In 2011, it arrived at the egg-shaped, 600-kilometer-long Vesta, orbiting for a year before departing for Ceres, where it arrived in 2015. ...The two asteroids, which together accou

This ball of gas is racing around the black hole at our galaxy’s heart Source:   By Daniel Clery, Science Magazine. Excerpt: Earlier this year, astronomers were looking for signs that S2, the star with the closest known orbit to the supermassive black hole thought to be at the center of the Milky Way, might—as predicted by Albert Einstein—deviate from the orbital path proscribed by Newtonian gravity. But while they were watching, they spied something else: three bright infrared flares unrelated to the star ...the signs of superheated gas racing almost as close to the black hole as possible without getting sucked in—at 30% the speed of light. Observing the action so close to the galactic center, known as Sagittarius A*, is extremely challenging because it is distant, small, and shrouded in gas and dust. The team used the world’s largest optical instrument, the European Southern Observatory’s Very Large Telescope in Chile, and combined the light of its four 8.2-

NASA Retires Kepler Space Telescope, Passes Planet-Hunting Torch Source:   NASA RELEASE 18-092. Excerpt: After nine years in deep space collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth. Kepler leaves a legacy of more than 2,600 planet discoveries from outside our solar system, many of which could be promising places for life. "As NASA's first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington. ...The most recent analysis of Kepler’s discoveries concludes that 20 to 50 percent of the

Move over, Hubble: Discovery of expanding cosmos assigned to little-known Belgian astronomer-priest Source:   By Daniel Clery, Science Magazine. Excerpt: Hubble’s Law, a cornerstone of cosmology that describes the expanding universe, should now be called the Hubble-Lemaître Law, following a vote by the members of the International Astronomical Union (IAU), the same organization that revoked Pluto’s status as a planet. The change is designed to redress the historical neglect of Georges Lemaître, a Belgian astronomer and priest who in 1927 discovered the expanding universe—which also suggests a big bang. Lemaître published his ideas 2 years before U.S. astronomer Edwin Hubble described his observations that galaxies farther from the Milky Way recede faster. ...In 1927 Lemaître calculated a solution to Albert Einstein’s general relativity equations that indicated the universe could not be static but was instead expanding. He backed up that claim with a limited

Scientists Double Down on Landing Sites for Sample-Collecting Mars Rover Source:   By Leonard David, Science Magazine. Excerpt: NASA’s Mars 2020 mission could visit two locations where microbial life may once have thrived. For NASA’s Mars 2020 rover, now being assembled at the agency’s Jet Propulsion Laboratory for launch in July 2020, the stakes could not be much higher. The $2.4 billion nuclear-powered rover is the most complex piece of machinery to ever make a ballistic beeline for the Red Planet. And after it lands in February 2021, its completion of one high-profile objective—collecting rock samples for eventual transport back to Earth—would ensure the rover sets the course for future Mars exploration for decades to come. But first, mission planners have to decide where on Mars this ambitious machine should actually go....

First moon outside the solar system could be as big as Neptune Source:   By Joshua Sokol, Science Magazine. Excerpt: With help from the Hubble Space Telescope, astronomers say they have found compelling evidence for the first known moon outside the solar system. ...this first reported “exomoon” is also strange: a Neptune-size megamoon, some 8000 light-years away, that looms over a giant planet, twice as large in the sky as Earth’s moon. ...Most theoretical models of planet formation struggle to produce such a hefty satellite. However, searches are biased toward the largest moons that might be out there, because bigger things are easier to detect. ...The first hints for the exomoon came from archival data from the Kepler probe, a NASA planet-hunting spacecraft, which looks for dips in brightness caused by unseen planets transiting in front of their suns. Alex Teachey and David Kipping, both of Columbia University, found that three dips, attributed to th

Japanese spacecraft drops a third rover on asteroid Ryugu Source:   By Dennis Normile, Science Magazine. Excerpt: After successfully dropping two small hopping rovers on the surface of asteroid Ryugu last month, the Japanese spacecraft Hayabusa2 today deployed another probe with a suite of instruments that will do some serious science. Hayabusa2, which arrived at Ryugu in June after a 3.5-year journey, descended to 51 meters above the asteroid and released the Mobile Asteroid Surface Scout (MASCOT). Twenty minutes later, the asteroid’s gravity had pulled the 10-kilogram probe, 30 by 30 by 20 centimeters in size, to the surface. ...MASCOT, jointly developed by the German Aerospace Center and the French National Centre for Space Studies, carries a camera, instruments to measure day-to-night thermal changes and check for magnetism, and an infrared spectral microscope to study the mineral composition and look for any evidence the asteroid once hosted

Cosmic conundrum: The disks of gas and dust that supposedly form planets don’t seem to have the goods Source:   By Adam Mann, Science Magazine. Excerpt: Astronomers have a problem on their hands: How can you make planets if you don’t have enough of the building blocks? A new study finds that protoplanetary disks—the envelopes of dust and gas around young stars that give rise to planets—seem to contain orders of magnitude too little material to produce the planets. “This work is telling us that we really have to rethink our planetary formation theories,” says astronomer Gijs Mulders of the University of Chicago in Illinois, who was not involved in the research. ...The brightness of radio waves emitted by dust in the disk can be used to give a reasonable estimate of its overall mass. ...In the new study, astronomers led by Carlo Manara of the European Southern Observatory in Munich, Germany, used [Atacama Large Millimeter Array (ALMA)] to compare the masses of pro

How Well Can the Webb Telescope Detect Signs of Exoplanet Life? Source:    By Lucas Joel, Eos/AGU. Excerpt: ...what NASA’s next-generation, space-based telescope will be able to do: “see the first light of the universe, watch galaxies collide, see stars and planets being born, find and study exoplanets.” ...recent research suggests that the [James Webb Space Telescope (JWST)] might have a tricky time detecting at least one telltale sign of life: oxygen in an exoplanet’s atmosphere. ... Noah Planavsky, a biogeochemist at Yale University, and a team of researchers recently found that a planet’s atmosphere with an extremely small amount of oxygen can still support life. This finding means there could be planets that have only minute oxygen levels—but that nonetheless harbor life—that would appear to be dead to JWST. ...JWST was not originally designed to scan distant planets for their oxygen concentrations. ...JWST’s oxygen-spotting prospects may be dim, but Jo

Hayabusa-2: Japan's rovers send pictures from asteroid Source:   By BBC News. Excerpt: Japan's space agency (JAXA) has made history by successfully landing two robotic explorers on the surface of an asteroid. The two small "rovers", which were despatched from the Hayabusa-2 spacecraft on Friday, will move around the 1km-wide space rock known as Ryugu. The asteroid's low gravity means they can hop across it, capturing temperatures and images of the surface. ...Hayabusa-2 reached the asteroid Ryugu in June this year after a three-and-a-half-year journey. ...Early on Thursday morning (GMT), Hayabusa-2 began descending towards the surface of Ryugu, preparing to eject its rovers. ...The 1kg rovers are equipped with wide-angle and stereo cameras to send back pictures. Spine-like projections from the edges of the hoppers are sensors that will measure surface temperatures on the asteroid. ...The diamond-shaped asteroid has a blackish-coloured surface, and rotates on its a

NASA’s TESS Starts Collecting Planets Source:   By Dennis Overbye, The New York Times. Excerpt: The satellite, launched in April, has already identified at least 73 stars that may harbor exoplanets, most of them new to astronomers. ...They all need to be confirmed by other astronomers....

Tiny spacecraft are breaking out of Earth’s orbit Source:   By Eric Hand, Science Magazine. Excerpt: Cheap, small satellites have swarmed into Earth orbit over the past decade, cutting the cost of studying our home planet from space. Now, these spacecraft, some no bigger than a briefcase, are becoming capable enough to venture into deep space—or at least the inner solar system. Two are halfway to Mars, more than a dozen planetary probes are in development, and scientists are coming up with ever more daring ideas for doing cheap, high-risk interplanetary science. ...Small satellites can be assembled from low-cost components and released by the dozen from a single rocket. But systems key to interplanetary flight, including propulsion, communication, and navigation, have traditionally been too bulky to fit into a small package. ...A mission called Mars Cube One (MarCO), ...showcases a miniature guidance, navigation, and control system developed by B

Parker Solar Probe Launches on NASA Voyage to ‘Touch the Sun’ Source:   By Kenneth Chang, The New York Times. Excerpt: Atop three columns of flame at 3:31 a.m. Eastern time, NASA’s Parker Solar Probe [ ] lifted toward space on Sunday. The launch was the second attempt to carry the spacecraft, which NASA touts will “touch the sun” one day, into orbit after a scrub early on Saturday. The probe — which will study the sun’s outer atmosphere as well as the stream of particles known as solar wind — was carried on top of a Delta IV Heavy rocket built and operated by United Launch Alliance, a joint venture between Boeing and Lockheed Martin. It is one of the most powerful rockets currently available. ...The spacecraft will eventually pass within 4 million miles of the sun’s surface, close enough to skim through the star’s outer atmosphere. ...At its closest approach, the outside of the spacecraft will reach 2,500 degrees Fahrenheit, or about

NASA’s Parker Solar Probe Is Named for Him. 60 Years Ago, No One Believed His Ideas About the Sun Source:   By Kenneth Chang, The New York Times. Excerpt: CHICAGO — It was 1958. Sputnik had launched only a year earlier.... But the beach ball-size spacecraft had no instruments to measure anything in space. ...It certainly looked like the vast expanses between planets were empty. And that is what most scientists believed. But not Eugene N. Parker, then a 31-year-old, no-name professor at the University of Chicago. In a foundational paper published in The Astrophysical Journal, Dr. Parker described how charged particles streamed continuously from the sun, like the flow of water spreading outward from a circular fountain. Almost no one believed him. “The prevailing view among some people was that space was absolutely clean, nothing in it, total vacuum,” Dr. Parker recalled during an interview at his home. ...The scientists who had reviewed the paper rejected his idea as ludicrous. Dr. Parker appeale

Dinosaur-Killing Asteroid Impact Made Huge Dead Zones in Oceans Source:   By Lucas Joel, Eos/AGU. Excerpt: About 66 million years ago, an asteroid roughly 10 kilometers wide hit Earth in what is today the Gulf of Mexico. It brought annihilation: All the dinosaurs except for the birds went extinct; forests around the planet vanished temporarily, killing off all bird species that lived in trees; dust and other aerosols blocked the Sun, and global temperatures took a nosedive. The world plunged into a state analogous to nuclear winter. Another fallout effect of the impact, according to new work, was a depletion of oxygen in the oceans triggered by rapid global warming following the impact and nuclear winter. Such anoxia, the researchers behind the work report, devastated marine life. What’s more, this episode of anoxia may have parallels to the rapid global warming and resulting ocean anoxia being wrought by human-driven climate change today. “The global warmi

The Kepler Revolution Source:   By Kimberly M. S. Cartier, Eos/AGU. Excerpt: The Kepler Space Telescope will soon run out of fuel and end its mission. Here are nine fundamental discoveries about planets aided by Kepler in the 9 years since its launch. ...Kepler Space Telescope, a small spacecraft that opened a large window to the many thousands of exoplanets strewn throughout the Milky Way ...was exhibiting the first signs of low fuel and ... would be functional for only a few more months. Its fuel tank hit critically low levels on 2 July, and mission scientists put Kepler into a no-fuel hibernation mode until its latest round of data can be downloaded on 2 August. ...1. Planets Are Everywhere, Equally. ...Through its unblinking gaze, Kepler discovered 4,571 planetary signatures, 2,327 of which have been confirmed as actual exoplanets. . ..2. The Solar System May Not Be Unique. ...With the help of an artificial intelligence algorithm, Kepler discovered a

Ancient craters on Mars reveal how the planet’s tilt has changed over time Source:   By Katherine Kornei, Science Magazine. Excerpt: Earth is a tilted planet—it lists by 23.5°. This “obliquity” causes the North Pole to sometimes tilt toward the sun and sometimes away, giving us the seasons. Now, researchers have revealed how Mars’s obliquity has changed over the last 3.5 billion years, results that could reveal how frequently water ice and snow would have melted to liquid on the Red Planet. To conduct the study, scientists assembled computer models of Mars with different obliquities and bombarded each version of the planet with asteroids. Elliptical craters—created by asteroids hitting the planet at shallow angles—tended to be more evenly distributed over the models with larger obliquities. On more upright planets, the elliptical craters tended to cluster around the equator. By comparing their models with the distribution of more than 1500 elliptical

What does Mars’ lake mean for the search for life on the Red Planet? Source:   By Lisa Grossman, Science Magazine. Excerpt: The search for life on Mars just got a lot more interesting. For decades, scientists have looked at ...finding regions where life could have taken root billions of years ago, when the Martian climate was warmer and wetter. But on July 25, researchers announced they had spotted signs of a large lake of liquid water hiding beneath thick layers of ice near the Red Planet’s south pole ( SN Online: 7/26/18 ). If the lake’s existence is confirmed, we could find microbes living on Mars today. That report changes the calculus for astrobiologists who want to protect any existing extraterrestrial life from being wiped out or obscured by introduced species from Earth.... Mars landers and rovers are cleaned to strict standards to avoid any possible contamination, even “without having anything you’d even call a pond,” says astrobiologist Lisa Pratt, NASA’s p

Outer space may have just gotten a bit closer Source:   By Paul Voosen, Science Magazine. Excerpt: ...A new study argues that the boundary between Earth’s atmosphere and outer space—known as the Kármán line—is 20 kilometers, or about 20%, closer than scientists thought. Though the new definition won’t make a difference for launching rockets and spacecraft, it could help clarify a legal debate that will set the rules for space policy—and commercial spaceflight—for years to come. Until now, most scientists have said that outer space is 100 kilometers away. At that point, it’s been thought, the speed needed to achieve lift in the superthin atmosphere is equal to the speed needed to simply orbit the planet; once there, a spacecraft’s horizontal pace would counteract the tug of Earth’s gravity. ...A close look shows that the traditional definition flies in the face of evidence, says Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Cent

Jupiter’s moon count reaches 79, including tiny ‘oddball’ Source:   By Emiliano Rodriguez Mega, Associated Press. Excerpt: Astronomers are still finding moons at Jupiter, 400 years after Galileo used his spyglass to spot the first ones. The latest discovery of a dozen small moons brings the total to 79, the most of any planet in our solar system. Scientists were looking for objects on the fringes of the solar system last year when they pointed their telescopes close to Jupiter’s backyard, according to Scott Sheppard of the Carnegie Institute for Science in Washington. They saw a new group of objects moving around the giant gas planet but didn’t know whether they were moons or asteroids passing near Jupiter. ...The team is calling one of the new moons an ‘oddball’ because of its unusual orbit. Sheppard’s girlfriend came up with a name for it: Valetudo, the great-granddaughter of the Roman god Jupiter. Valetudo is in Jupiter’s distant, outer swarm of moons that circles in the opposite dire

In a first, astronomers witness the birth of a planet from gas and dust Source:   By Daniel Clery, Science Magazine. Excerpt: In the first convincing observation of its kind, astronomers have directly imaged a newborn planet still forming around its star. The planet, hotter than any in our solar system, supports what astronomers have long believed: that such bodies are born of the disks of gas and dust that coalesce around young stars. “After decades of speculation, it’s nice to actually see one. It’s very comforting,” says astronomer Kevin Heng of the University of Bern in Switzerland, who was not involved in the work. The initial discovery was led by astronomer Miriam Keppler of the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany. Since 2015, her team has been regularly surveying hundreds of young stars for signs of exoplanets with a next-generation imaging instrument called SPHERE (for Spectro-Polarimetric High-contrast Exoplanet Research), at

Japan’s new asteroid probe reaches its target after 3.2-billion-kilometer journey Source:   By Dennis Normile, Science Magazine. Excerpt: SAGAMIHARA, JAPAN—After 3.5 years traveling 3.2 billion kilometers through space, Japan’s Hayabusa2 spacecraft officially arrived at the asteroid it will land on later this year to pick up surface and subsurface soil and rock samples and—hopefully—return them to Earth for analysis. The findings are expected to shed light on the materials that existed in the early solar system and the formation and evolution of planets and their arrangement. They might provide evidence for the theory that asteroids and comets are one source of Earth’s water and its amino acids—the building blocks of life. ...Next spring, Hayabusa2 will blast a crater into Ryugu using a 2-kilogram projectile with a hardened copper nose traveling at 2000 meters per second. ...Images of the impact are expected to shed light on how craters are for

The Case of the Missing Lunar Heat Flow Data Is Finally Solved Source:   By Sarah Stanley, Eos/AGU. Excerpt: Decades-old data analyzed for the first time suggest that astronauts’ disturbance of the Moon surface increased solar heat intake, warming the ground below. During the Apollo 15 and 17 missions, astronauts installed four temperature-sensing probes in shallow, 1.0- to 2.4-meter-deep holes drilled into the Moon. They aimed to measure how much of the Moon’s heat was lost to space, which could provide insights into the origin and the differentiation history of the Moon. The Apollo Heat Flow Experiment ran from 1971 to 1977.  ...In 2011, the researchers reported that they had found about 10% of the missing tapes at the Washington National Records Center in Maryland. ...They found that from 1974 until the Heat Flow Experiment concluded in 1977, the lunar subsurface warmed up, with greater warming occurring at shallower depths. This continued a w

NASA rover hits organic pay dirt on Mars Source:   By Paul Voosen, Science Magazine. Excerpt: In its quest to find molecules that could point to life on Mars, NASA's Curiosity rover has struck a gusher. Since Curiosity landed in 2012, it has sifted samples of soil and ground-up rock for signs of organic molecules—the complex carbon chains that on Earth form the building blocks of life. Past detections have been so faint that they could be just contamination. Now, samples taken from two different drill sites on an ancient lakebed have yielded complex organic macromolecules that look strikingly similar to the goopy fossilized building blocks of oil and gas on Earth. At a few dozen parts per million, the detected levels are 100 times higher than previous finds. Although the team cannot yet say whether these molecules stem from life or a more mundane geological process, they demonstrate that organics can be preserved for billions of years in the

This asteroid came from another solar system—and it’s here to stay Source:   By Daniel Clery, Science Magazine. Excerpt: While astronomers around the world had their eyes fixed last year on ‘Oumuamua, a lump of rock from another planetary system that whizzed through ours, little did they know that another interstellar interloper was quietly living among us. And this one appears to have been here for billions of years. Astronomers first spotted the object, an asteroid called 2015 BZ509 that is orbiting close to Jupiter, in 2014. They knew it was unusual because it was traveling around the solar system in the opposite direction as almost everything else. ...Astronomers have found other objects in “retrograde” orbits, perhaps knocked off course by passing too close to a giant planet, but 2015 BZ509’s orbit was the weirdest of all because it is also elongated and out of alignment with the planets and other bodies. To find out why, a pair of astronomers ran a s

Yes, Pluto is a planet Source:   David Grinspoon and Alan Stern, The Washington Post. Excerpt: Three years ago, NASA’s New Horizons, the fastest spaceship ever launched, raced past Pluto, spectacularly revealing the wonders of that newly seen world. This coming New Year’s Eve — if all goes well on board this small robot operating extremely far from home — it will treat us to images of the most distant body ever explored, provisionally named Ultima Thule. We know very little about it, but we do know it’s not a planet. Pluto, by contrast — despite what you’ve heard — is. Why do we say this? ...We use “planet” to describe worlds with certain qualities. When we see one like Pluto, with its many familiar features — mountains of ice, glaciers of nitrogen, a blue sky with layers of smog — we and our colleagues quite naturally find ourselves using the word “planet” to describe it and compare it to other planets that we k

Gaia’s Map of 1.3 Billion Stars Makes for a Milky Way in a Bottle Source:   By Dennis Overbye, The New York Times. Excerpt: ...astronomers in Europe released a three-dimensional map of the Milky Way. It is the most detailed survey ever produced of our home galaxy. It contains the vital statistics of some 1.3 billion stars — about one percent of the entire cosmic panoply of which Earth and the sun are part. Not to mention measurements of almost half a million quasars, asteroids and other flecks in the night. Analyzing all these motions and distances, astronomers say, could provide clues to the nature of dark matter. The gravity of that mysterious substance is said to pervade space and sculpt the arrangements of visible matter. Gaia’s data could also reveal information about the history of other forces and influences on our neighborhood in the void. And it could lead to a more precise measurement of a historically troublesome parameter called the Hubble constant, which describes how

Diamonds in a Meteorite May Be a Lost Planet’s Fragments Source:   By Nicholas St. Fleur, The New York Times Excerpt: In 2008, chunks of space rock crashed in the deserts of Sudan. Diamonds discovered inside one of the recovered meteorites may have come from a destroyed planet that orbited our sun billions of years ago, scientists said on Tuesday. If confirmed, they say, it would be the first time anyone has recovered fragments from one of our solar system’s so-called “lost” planets. ... Dr. Gillet’s colleague Farhang Nabiei made the discovery while taking high-resolution images of a meteorite that had landed ...about a decade ago. The space rock is classified as ureilite, a type of rare meteorite that has embedded within it several different types of minerals. And inside this one, they found diamonds. The nano-sized gems were ...far from crystal clear. They were riddled with tiny imperfections, called inclusions, made of chromite, phosphate and iron-nickel su

NASA Television to Air Launch of Next Planet-Hunting Mission Source:   By NASA Media Advisory M18-059 Excerpt: On a mission to detect planets outside of our solar system, NASA’s Transiting Exoplanet Survey Satellite (TESS) is scheduled to launch no earlier than 6:32 p.m. EDT Monday, April 16. Prelaunch mission coverage will begin on NASA Television and the agency’s website Sunday, April 15, with three live briefings. TESS is NASA’s next step in the search for planets outside of our solar system, known as exoplanets, including those that could support life. The mission is expected to catalog thousands of planet candidates and vastly increase the current number of known exoplanets. TESS will find the most promising exoplanets orbiting relatively nearby stars, giving future researchers a rich set of new targets for more comprehensive follow-up studies, including the potential to assess their capacity to harbor life.... 

History of Mars’s Water, Seen Through the Lens of Gale Crater Source:   By Ramin Skibba, AGU-Eos Excerpt: Past research indicates that the Red Planet may have been a very different world more than 3 billion years ago, with warmer weather, flowing rivers, lakes, and possibly even oceans of liquid water. These conditions would have been much more hospitable to nascent life-forms, if they existed. However, recent research is uncovering a different story. “There have been two competing viewpoints about the Martian climate at this time: the traditional warm-and-wet view and the view that Mars was always cold and icy,” explained Jeffrey Andrews-Hanna, a Mars-focused planetary scientist at the University of Arizona. Now, enter a third scenario: Billions of years ago, “Mars never really experienced a temperate Earth-like climate,” Andrews-Hanna added. Instead, a body of recent evidence points to an arid early Mars with pockets of wet patches.... 

NASA’s new satellite brings the search for Earthlike exoplanets closer to home Source:   By Daniel CleryMar, Science. Excerpt: Thanks to NASA's pioneering Kepler probe, we know our galaxy is teeming with exoplanets ...more than 2600 confirmed exoplanets, implying hundreds of billions in the Milky Way. The new efforts Earth-size planets whose composition, atmosphere, and climate—factors in whether they might be hospitable to life—could be studied. Leading the charge is the Transiting Exoplanet Survey Satellite (TESS), a NASA mission due for launch on 16 April. The brainchild of researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, the $337 million TESS project aims to identify at least 50 rocky exoplanets—Earth-size or bigger—close enough for their atmospheres to be scrutinized by the much larger James Webb Space Telescope (JWST), due for launch in 2020. ...Like Kepler, TESS finds planets by staring at stars and looking

Surprising meteorite discovery points to early solar system chaos Source:   By Paul VoosenMar, Science. Excerpt: The stately solar system of today was in turmoil in its first several million years, theorists believe, with giant planets sowing chaos as they strayed far from their current orbits. But corroborating evidence has been thin—until now. Scientists have found a new window into the early dynamics: a curious chemical divide in the dozens of species of meteorites. work presented last week at the Lunar and Planetary Science Conference here, a group of German geochemists ...tested 32 meteorites representing nearly all known types and found that "any meteorite you take, it belongs to either one of these groups," says Thorsten Kleine, a geochemist at the University of Münster in Germany who led the work. Those divergent chemistries imply distinct origin stories for asteroids, the parent bodies of most meteorites. One group formed

Meet TESS, Seeker of Alien Worlds Source:   By Dennis Overbye, The New York Times. For GSS A Changing Cosmos chapter 8. Excerpt: ...No earlier than 6:32 p.m. on April 16, ...a little spacecraft known as the Transiting Exoplanet Survey Satellite, or TESS, bristling with cameras and ambition, will ascend on a SpaceX Falcon 9 rocket in a blaze of smoke and fire and take up a lengthy residence between the moon and the Earth. There it will spend the next two years, at least, scanning the sky for alien worlds. TESS is the latest effort to try to answer questions that have intrigued humans for millenniums and dominated astronomy for the last three decades: Are we alone? Are there other Earths? Evidence of even a single microbe anywhere else in the galaxy would rock science. ...“Most of the stars with planets are far away,” said Sara Seager, a planetary scientist at the Massachusetts Institute of Technology and a member of the TESS team, referring to Kepler

Mars’ oceans formed early, possibly aided by massive volcanic eruptions Source:   By Robert Sanders, UC Berkeley News. For GSS A Changing Cosmos chapter 7. Excerpt: A new scenario seeking to explain how Mars’ putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million years earlier and were not as deep as once thought. ...The proposal by UC Berkeley geophysicists links the existence of oceans early in Mars history to the rise of the solar system’s largest volcanic system, Tharsis, and highlights the key role played by global warming in allowing liquid water to exist on Mars. “Volcanoes may be important in creating the conditions for Mars to be wet,” said Michael Manga, a UC Berkeley professor of earth and planetary science and senior author of a paper appearing in Nature this week and posted online March 19. Those claiming that Mars never had oceans of liquid water often point to the fact that e

Jupiter’s chaotic storms have roots deep beneath its surface Source:   By Paul Voosen, Science. Excerpt: The gaseous veil of Jupiter’s surface has long cast a pall over scientists’ quest to understand the giant planet’s depths. In particular, researchers have debated whether the bands of east-west winds ...extend deeper into the planet, or are merely superficial. Now, a series of papers from NASA’s Juno spacecraft, published today in Nature, has revealed that the roots of Jupiter’s winds indeed run deep. ...Juno’s scientists discovered an asymmetry in Jupiter’s north-south gravitational field that reflected shifting masses driven by rising winds from 3000 kilometers deep within the planet. These flows of hydrogen and helium, the team shows, are driven up by energy lost from the planet’s deeper interior, which rotates like a solid because of crushing high pressures....    See also Scientific American article:

India plans to land near moon's south pole Source:   By Pallava Bagla, Science. Summary: Sometime this summer, an Indian spacecraft orbiting over the moon's far side will release a lander. The craft will ease to a soft landing just after lunar sunrise on an ancient, table-flat plain about 600 kilometers from the south pole. There, it will unleash a rover into territory never before explored at the surface. That's the ambitious vision for India's second voyage to the moon in a decade, due to launch in the coming weeks. If Chandrayaan-2 is successful, it will pave the way for even more ambitious Indian missions, such as landings on Mars and an asteroid, as well as a Venus probe. Lunar scientists have much at stake, too. Chandrayaan-2 will collect data on the moon's thin envelope of plasma, as well as isotopes such as helium-3, a potential fuel for future fusion energy reactors. And it will follow up on a stunning discovery by India's first lunar foray, whi

Looking to the Future of Exoplanet Science Source:   By Kimberly M. S. Cartier, Eos/AGU Excerpt: Upcoming missions seeking to unravel the secrets of exoplanets abound. An informal survey of astronomers revealed which of those projects they most eagerly await. ...Wide Field Infrared Survey Telescope (WFIRST)... expected launch is around 7 years not a dedicated exoplanet telescope. ...WFIRST will be an imaging-only telescope hosting two instruments, a wide-field camera and a coronagraph,.... European Space Agency’s (ESA) upcoming planet hunter, called Planetary Transits and Oscillations of Stars (PLATO), ... 6-year mission is not scheduled to launch until 2024, its goal of monitoring more than 1 million stars for signals of planetary transits.... NASA’s Transiting Exoplanet Survey Satellite (TESS) currently scheduled to lift off from Cape Canaveral Air Force Station in Florida this year, sometime from early March to late June. ...TESS will conduct

Exposed subsurface ice sheets in the Martian mid-latitudes Source:   By Colin M. Dundas et al, Science Abstract: Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle. We investigated eight of these locations and found that they expose deposits of water ice that can be >100 meters thick, extending downward from depths as shallow as 1 to 2 meters below the surface. The scarps are actively retreating because of sublimation of the exposed water ice. The ice deposits likely originated as snowfall during Mars’ high-obliquity periods and have now compacted into massive, fractured, and layered ice. We expect the vertical structure of Martian ice-rich deposits to preserve a record of ice deposition and past climate....