Astro Blog

By Hannah Richter , Science.  Excerpt: In the late 2000s, planetary scientists scoured data gathered by NASA’s Cassini mission, a Saturn orbiter, about the planet’s mysterious icy moon Titan. Their exciting conclusion: The frozen world harbored an ocean sloshing around tens of kilometers beneath a thick ice shell. The ocean, hundreds of kilometers deep itself, might even be a cauldron for the “prebiotic” organic chemistry that led to life on Earth, they proposed. Now, nearly 2 decades later, researchers think they may have gotten the story all wrong. Research  presented today  here at the American Geophysical Union’s annual meeting and  published in  Nature  claims that although Titan may have once harbored a liquid ocean, today it is frozen, except for smaller melted zones deep beneath the surface. If true, the discovery will upend the long-standing assumption that Saturn’s biggest moon is a water world, like other moons in the outer Solar System,  in...

By PAUL VOOSEN , Science.  Excerpt: In its youth, the Solar System underwent a momentous upheaval: Gravitational tugs between the giant planets threw them off track, causing Jupiter’s orbit to jump closer to the Sun, while Saturn, Uranus, and Neptune were flung outward. The gravity of the rampaging giants scattered Pluto and other icy bodies to the Kuiper belt, shepherded the asteroid belt into its current location, and sent countless bodies crashing into the inner Solar System. For many years, researchers believed this “giant planet instability” occurred 600 million years after the Solar System’s birth 4.57 billion years ago, based on the ages of impact craters mapped on the Moon. Recently, evidence has mounted that it  occurred much earlier . And now, some researchers are homing in on a more precise date, just 60 million years after the Solar System’s formation, based on an analysis of rare meteorites derived from an ancient asteroid family, published today in Science. ...

https://www.sciencemag.org/news/2020/07/how-nasa-s-new-rover-will-search-signs-ancient-life-mars Source:   By Kelso Harper, Joel Goldberg, Science Magazine.  Excerpt: [See movie also] If NASA realizes its midsummer dream, a spacecraft will blast off from Cape Canaveral, Florida, sometime between 30 July and 15 August, destined to ignite the next generation of Mars exploration. The mission aims to deliver the space agency’s latest rover, Perseverance, to an uncharted crater known as Jezero—an ancient lake bed that could offer a window into Mars’s climatic history. Perseverance will carry many tools and instruments, including a small helicopter and a novel array of 43 sample tubes, robotic arms, and multiple drills, which will bore into the martian surface for chalk-size cores of rock and soil. The cores will eventually make their way back to Earth in a sample return campaign, a joint effort between NASA and the European Space Agency. Should they contain organic compounds, the...

https://www.sciencemag.org/news/2020/06/nasa-s-new-rover-will-collect-martian-rocks-and-clues-planet-s-ancient-climate Source:  By Paul Voosen, Science Magazine.  Excerpt: NASA’s newest Mars rover, Perseverance, is going back in time to the bottom of a vanished lake. If all goes well, in February 2021 it will land in Jezero crater and pop the dust covers off its camera lenses. Towering in front of it, in all likelihood, will be a 60-meter cliff of mudstone: the edge of a fossilized river delta. These lithified martian sediments could hold answers to urgent questions about the earliest days of Earth’s chilly, parched neighbor: How did this pintsize planet, so distant from a faint young Sun, support liquid water on its surface? How much water was there, and how long did it persist? And did Mars ever spawn life?....  See also Martian Chronicler, Science Magazine 2020 June 26 article by Paul Voosen [ http://science.sciencemag.org/content/368/6498/1416 ]

https://www.sciencemag.org/news/2020/06/mars-mission-would-put-china-among-space-leaders Source:    By Dennis Normile, Science Magazine.  Excerpt: NASA’s Perseverance rover may have company on the Red Planet. China aims to leap to the front ranks in planetary exploration with an ambitious Mars mission, its first independent bid to reach the planet. Tianwen-1—“quest for heavenly truth”—consists of not only an orbiter, but also a lander and a rover, a trifecta no other nation has accomplished on its first Mars bid. “A successful landing would put China among elite company,” says Mason Peck, an aerospace engineer at Cornell University....

https://www.nytimes.com/2020/06/23/science/mars-helicopter-nasa.html URL Source:  By Kenneth Chang, The New York Times.  Excerpt: As part of its next Mars mission, NASA is sending an experimental helicopter to fly through the red planet’s thin atmosphere....  

https://www.sciencemag.org/news/2020/01/how-many-our-comets-come-alien-solar-systems Source:   By Eva Frederick, Science Magazine. Excerpt: Comets are generally thought to originate in our Solar System, made up of the leftover gas and rocks thrown out as the planets formed. The recent arrival of two interstellar objects—a rock named ‘Oumuamua and a flashy comet called Borisov—have challenged that assumption. Tom Hands, an astrophysicist at the University of Zurich’s Institute for Computational Science and his co-author Walter Dehnen at Ludwig Maximilian University of Munich used mathematical models to estimate just how many long-period comets—those that take 200 years or longer to circle the Sun—could be interstellar visitors. ...We estimated from the study that there should be 100,000 ‘Oumuamua-style small rocks and 100 Borisov-style comets in the Solar System. Making far more conservative estimates for how long these objects would survive in the Solar System [shorter than 10 ...

https://www.nytimes.com/2019/03/18/science/ultima-thule-new-horizons.html Source:   By Kenneth Chang, The New York Times. Excerpt: ...New Horizons traveled some 4 billion miles to take a close-up look at this 22-mile-long world in the solar system’s icy Kuiper belt beyond Neptune; it is officially designated as 2014 MU69 and nicknamed Ultima Thule. ...a small shard that has been frozen and almost unchanged since it formed 4.5 billion years ago. Ultima Thule was ... full of surprises. The shape turned out to be unlike anything seen in the solar system. ...two objects that at some stage touched and stuck together, like a snowman. Then the scientists discovered that the two lobes of Ultima Thule were not spherical, but more like lumpy pancakes. The larger lobe is also flatter than the smaller one. ...a change from older ideas of planetary formation: that objects called planetesimals grew slowly and steadily in size. Ultima Thule suggests an alternative scenario in which a bunch of...

http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190102 Source:  By New Horizons Mission. Excerpt: Scientists from NASA's New Horizons mission released the first detailed images of the most distant object ever explored — the Kuiper Belt object nicknamed Ultima Thule. Its remarkable appearance, unlike anything we've seen before, illuminates the processes that built the planets four and a half billion years ago. "This flyby is a historic achievement," said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado. "Never before has any spacecraft team tracked down such a small body at such high speed so far away in the abyss of space. New Horizons has set a new bar for state-of-the-art spacecraft navigation." The new images — taken from as close as 17,000 miles (27,000 kilometers) on approach — revealed Ultima Thule as a "contact binary," consisting of two connected spheres. End to end, the...

https://www.sciencemag.org/news/2019/01/japans-asteroid-mission-faces-breathtaking-touchdown Source:   By Dennis Normile, Science Magazine. Excerpt: "By looking at the details of every asteroid ever studied, we had expected to find at least some wide flat area suitable for a landing," says Yuichi Tsuda, Hayabusa2's project manager at the Japan Aerospace Exploration Agency's Institute of Space and Astronautical Science (ISAS), which is headquartered in Sagamihara. Instead, when the spacecraft reached Ryugu in June 2018—at 290 million kilometers from Earth—it found a cragged, cratered, boulder-strewn surface that makes landing a daunting challenge. The first sampling touchdown, scheduled for October, was postponed until at least the end of this month, and at a symposium here on 21 and 22 December, ISAS engineers presented an audacious new plan to make a pinpoint landing between closely spaced boulders....

Source:   By Kenneth Chang, The New York Times Excerpt: ...one might think that meteorites that fall on Earth ought to be just like the asteroids that pass through Earth’s neighborhood. “That’s what everybody would have expected,” said Philipp R. Heck, the curator in charge for the meteorite and physical geology collections at the Field Museum of Natural History in Chicago. Planetary scientists were surprised almost a decade ago when they discovered that the most plentiful types of meteorites they had collected and studied on Earth were actually not common in space. In a paper published Monday by the journal Nature Astronomy, an international team of researchers led by Dr. Heck says it has uncovered part of the explanation. Mineralogical evidence in some meteorites had already pointed to a cataclysmic collision in the asteroid belt about 466 million years ago — long before dinosaurs, when multicellular animals were still fairly new. (Dr. Heck estimated that any skywatchers back...

Source:   By Jonathan Corum, The New York Times Excerpt: NASA’s mission to grab pieces of an asteroid and bring them back to Earth took off on Thursday night. “You’ll be glad to know we got everything just exactly perfect,” Dante Lauretta, the mission’s principal investigator, said at a news conference after the launch of the Osiris-Rex spacecraft. The craft began its journey on top of an Atlas 5 rocket that lifted off into the summer sky above Cape Canaveral, Fla. Seven years from now, the craft is to return and parachute a capsule with the asteroid bits into a Utah desert, giving scientists a window to some of the material that made up the early solar system, including some of the molecules that gave rise to life on Earth.... http://www.nytimes.com/interactive/2016/09/08/science/space/nasa-osiris-rex-launch.html

Source:   By Jonathan Corum, The New York Times Excerpt: NASA’s mission to grab pieces of an asteroid and bring them back to Earth took off on Thursday night. “You’ll be glad to know we got everything just exactly perfect,” Dante Lauretta, the mission’s principal investigator, said at a news conference after the launch of the Osiris-Rex spacecraft. The craft began its journey on top of an Atlas 5 rocket that lifted off into the summer sky above Cape Canaveral, Fla. Seven years from now, the craft is to return and parachute a capsule with the asteroid bits into a Utah desert, giving scientists a window to some of the material that made up the early solar system, including some of the molecules that gave rise to life on Earth.... http://www.nytimes.com/interactive/2016/09/08/science/space/nasa-osiris-rex-launch.html

Source:   By Daniel Clery, Science Excerpt: ...The planet hunt accelerated with the launch of NASA’s Kepler spacecraft in 2009, and the 2500 worlds it has discovered added statistical heft to the study of exoplanets—and yet more confusion. Kepler found that the most common type of planet in the galaxy is something between the size of Earth and Neptune—a “super-Earth,” which has no parallel in our solar system and was thought to be almost impossible to make.  ...Other planetary systems looked nothing like our orderly solar system, challenging the well-worn theories that had been developed to explain it. ...The traditional model of how stars and their planets form dates back to the 18th century, when scientists proposed that a slowly rotating cloud of dust and gas could collapse under its own gravity. ...This scenario naturally produces a planetary system just like our own: small, rocky planets with thin atmospheres close to the star, a Jupiter-like gas giant just beyond the...

Source:   NASA RELEASE 15-032. Excerpt: NASA scientists have determined that a primitive ocean on Mars held more water than Earth's Arctic Ocean and that the Red Planet has lost 87 percent of that water to space.... Scientists have been searching for answers to why this vast water supply left the surface. Details of the observations and computations appear in Thursday’s edition of Science magazine.... “With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer,” said Michael Mumma, a senior scientist at Goddard and the second author on the paper. See also New York Times article Ancient Mars Had an Ocean, Scientists Say . http://www.nasa.gov/press/2015/march/nasa-research-suggests-mars-once-had-more-water-than-earth-s-arctic-ocean/

Source:   Jia-Rui C. Cook ,  NASA Press Rrelease 13-280  Excerpt: NASA's Voyager 1 spacecraft officially is the first human-made object to venture into interstellar space. The 36-year-old probe is about 12 billion miles (19 billion kilometers) from our Sun. ...Traveling at the speed of light, a signal from Voyager 1 takes about 17 hours to travel to Earth. ...Voyager 1 has been traveling for about one year through plasma, or ionized gas, present in the space between stars.  ...A coronal mass ejection, or a massive burst of solar wind and magnetic fields, that erupted from the sun in March 2012 provided scientists the data they needed ...eventually arrived at Voyager 1's location 13 months later.... On April 9 [2013], Voyager 1's plasma wave instrument detected the movement. ...the spacecraft was bathed in plasma more than 40 times denser than what they had encountered in the outer layer of the heliosphere. Density of this sort is to be expected in interstella...

Source:    NASA RELEASE: 11-402 Excerpt:  NASA's Voyager 1 spacecraft has entered a new region between our solar system and interstellar space.  ...Although Voyager 1 is about 11 billion miles (18 billion kilometers) from the sun, it is not yet in interstellar space.  ...Scientists previously reported the outward speed of the solar wind had diminished to zero in April 2010, marking the start of the new region.  …"We've been using the flow of energetic charged particles at Voyager 1 as a kind of wind sock to estimate the solar wind velocity," said Rob Decker,... "We've found that the wind speeds are low in this region and gust erratically. For the first time, the wind even blows back at us. We are evidently traveling in completely new territory. ...For more information about the Voyager spacecraft, visit: http://www.nasa.gov/voyager  www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html

Source:   Deborah Kent, Physics Today Excerpt:  ... sensational news of Neptune’s observation ... at the Berlin Observatory just after midnight on 23 September 1846. The discovery was seen as a remarkable accomplishment of celestial mechanics. ...the planet had been mathematically predicted before it was observed. … In the summer of 1845, French scientist Urbain Jean Joseph LeVerrier also started to study the irregularities of the orbit of Uranus. … LeVerrier sent his request to Johann Galle at the Berlin Observatory. ...after less than an hour of observing, Galle reported “there is a star of the 8th magnitude in such and such a position, whereupon I immediately exclaimed: that star is not on the map!” www.physicstoday.org/resource/1/phtoad/v64/i12/p46_s1

Source:      NASA RELEASE: 11-288 Excerpt: NASA is giving the public the power to journey through the solar system using a new interactive Web-based tool. The "Eyes on the Solar System" interface combines video game technology and NASA data to create an environment for users to ride along with agency spacecraft and explore the cosmos. Screen graphics and information such as planet locations and spacecraft maneuvers use actual space mission data. ..."Eyes on the Solar System" and an introduction video are available at: solarsystem.nasa.gov/eyes www.nasa.gov/home/hqnews/2011/sep/HQ_11-288_System_Eyes.html

Source:   NASA Excerpt: There are many types of small bodies in the solar system, but none may be as dramatic as comets.  …Comets also have a big influence when they collide with Earth. …Some scientists argue that colliding comets early in Earth's development contributed much of Earth's water. Some scientists also postulate that comets could have delivered organic molecules critical to the formation of life.... solarsystem.nasa.gov/yss/display.cfm