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SOFIA Observations of Ceres Show You Can’t Judge an Asteroid by Its Cover(ing)

Animated sequence of images from NASA's Dawn spacecraft showing northern terrain on the sunlit side of Ceres. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Animated sequence of Ceres from NASA’s Dawn spacecraft. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The dwarf planet Ceres, at 587 miles wide the largest object in the main asteroid belt between Mars and Jupiter, has a different surface composition than previously thought—and it took NASA and DLR’s Boeing 747-based SOFIA observatory to make the distinction. By observing Ceres in mid-infrared, only possible from high altitudes above infrared-absorbing water vapor, SOFIA found that Ceres is covered in silicates—pyroxenes—that likely came from impacts, the result of infalling material from elsewhere in the asteroid belt…the “dust” of asteroid collisions.

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Cassini Has Just Taken the Best Picture of Daphnis Yet!

Image of Daphnis captured by Cassini on Jan. 18, 2017. (NASA/JPL-Caltech/SSI)

Image of Daphnis captured by Cassini on Jan. 16, 2017. (NASA/JPL-Caltech/SSI)

Hello, Daphnis! On January 16, 2017, the Cassini spacecraft captured the best photo yet of Daphnis, a 5-mile-wide shepherd moon that orbits Saturn inside the Keeler Gap at the outermost edge of the A ring (and also just so happens to be my personal favorite moon of Saturn!) The raw image arrived on Earth today, and it’s just beautiful.

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This Star in Our Galaxy is Almost as Old as the Entire Universe

HD 140283 is a subgiant star located about 200 light-years away in the constellation Libra, and is the oldest known star. (Photo by Digitized Sky Survey/NASA/GSF/Sky Server)

Like anything else, stars have life spans. They are born (from collapsing clouds of interstellar dust), they go through a long main phase where they fuse various elements in their cores, and eventually they die when they run out of fuel. The finer details of these steps are based on what the star is made of, how massive it is, and what sort of company it keeps. Stars like our Sun have lifespans in the 9-10 billion year range—of which ours is near the middle—but other stars can have much shorter or longer lifespans, and as astronomers look out into the galaxy they can find stars at all different phases of their lives…of course, the longer a phase lasts, the more likely it is to find stars existing within it. We’ve found stars that are only a few thousand years old and we know of regions where stars are, right now, in the process of being born, but what is the oldest star we know of?

Actually, it’s not all that far away, in cosmic terms. Just 190 light-years distant in our own galaxy, HD 140283 (aka the Methuselah star) is, as of 2013, the oldest star ever discovered. Based on its stage as a subgiant and its remarkably low amount of heavy elements, astronomers have estimated the age of this star as 14.3 billion years old. Now this number is actually more than the estimated age of the Universe itself, but don’t worry—there’s a reason for that.

Read the rest of this story by astronomer Phil Plait on Slate here: The Oldest Known Star in the Universe.

This is Jupiter Seen from Mars

Jupiter and its four largest moons imaged by the HiRISE camera in orbit around Mars on Jan. 11, 2007. (NASA/JPL/University of Arizona)

Jupiter and its four largest moons imaged by the HiRISE camera in orbit around Mars on Jan. 11, 2007. (NASA/JPL/University of Arizona)

The HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter (MRO) is specifically designed to take super high-resolution images of the surface of Mars but it also does a pretty darn good job capturing pictures of other objects too—like Jupiter and its Galilean moons, several hundred million miles away! The image above was captured in expanded color (that is, it includes wavelengths in infrared) by HiRISE on January 11, 2007, and shows the giant planet from Mars orbit.

Mars and Jupiter were at opposition at the time, only about 345 million miles apart.

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Gene Cernan, the “Last Man on the Moon,” Has Died at 82

Photo of Gene Cernan in the Apollo 17 CSM during return from the Moon in 1972. (NASA/JSC)

Photo of Gene Cernan in the Apollo 17 CSM during return from the Moon in 1972. (NASA/JSC)

Sad news today: Eugene A. Cernan, former NASA astronaut and one of the twelve people who walked on the Moon during the Apollo program, died today at the age of 82.

“It is with very deep sadness that we share the loss of our beloved husband and father,” Cernan’s family said in a news release from NASA.  “Our family is heartbroken, of course, and we truly appreciate everyone’s thoughts and prayers. Gene, as he was known by so many, was a loving husband, father, grandfather, brother and friend.”

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Friday Fun: Plop Plop, Fizz Fizz…in Zero-G

During his 340-day-long One-Year Mission in 2015-2016 NASA astronaut Scott Kelly conducted—and was the subject of—countless experiments on the effects of long-duration space travel aboard the ISS. But he did manage to have a little fun too; the video above shows what happens to a blob of water free-floating in microgravity (that’s the technical term for zero-g in orbit) when Kelly adds some food coloring and a piece of Alka-Seltzer. The results are interesting to say the least as well as quite beautiful…be sure to watch in high-definition to catch the castoff watery “meteors!”

Learn more about the One-Year Mission here (and h/t to Aeon Magazine editor Corey Powell for the video!)

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