Astro Blog

http://www.sciencemag.org/news/2018/08/tiny-spacecraft-are-breaking-out-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 ...

https://www.nytimes.com/2018/08/11/science/parker-solar-probe-launch.html 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 [ http://parkersolarprobe.jhuapl.edu/ ] 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 ab...

https://www.nytimes.com/2018/08/10/science/eugene-parker-solar-wind-nasa-probe.html 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 app...

https://eos.org/articles/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 w...

https://eos.org/features/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 discover...

http://www.sciencemag.org/news/2018/07/ancient-craters-mars-reveal-how-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 ellipt...

https://www.sciencenews.org/article/what-does-mars-lake-mean-search-life-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...