Author Archives: Jason Major
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.
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.
The European Southern Observatory has begun imaging the Sun for the first time, using its Atacama Large Millimeter/submillimeter Array (ALMA)—a suite of large dish-type telescopes located on a plateau 16,000 feet above sea level in the arid Chilean Andes. ALMA’s capabilities to observe in millimeter and submillimeter wavelengths allow imaging of the Sun’s dynamic chromosphere and the features within it, such as the center of a sunspot (above) that’s easily twice the size of Earth.
Read more here from ESO: ALMA Starts Observing the Sun
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.
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.
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.”