Double Post: Mini Stars & Morning Micrometeorites on Mercury

Alliteration is accessible to all! Okay I’m done. Start some science! Really done this time.  Today’s double post covers the smallest of stars, still larger than most planets, and the only weather Mercury will ever have. Humans are naturally interested in the extremes, the biggest, smallest, fastest, hottest, coldest, and every other characteristic outlier.  With stars, being so huge and powerful, we are often more interested in the largest, hottest, and most energetic.  Though on the opposite end of the spectrum, Cambridge University astronomers have discovered the smallest star in the known universe. The star, a red dwarf, has the...

Ceres: Before and After

Remember a few months ago when excitement was high about seeing the surface of the dwarf planet Ceres for the first time with the Dawn spacecraft? Remember when the pictures were simple and blurry and looked more like a conspiracy theorist’s UFO pictures than another celestial body? Remember when I wrote about how cool it will be when we become the first humans in history, and the first form of life to ever see the surface of this object? The lead up to the Ceres encounter is well summed up in the NASA video from right before the encounter. I...

Hyperion the Sponge Moon

A couple of days ago, the still-active Cassini spacecraft orbiting around Saturn performed a flyby of the small Moon Hyperion, taking high resolution photos of the surface, and showing the sponge-like surface of the moon in a different light. Hyperion is a moderate 250 kilometers wide, yet it doesn’t tug very hard on Cassini.  Performing measurements of its surface gravity, Cassini has shown that the moon is mostly empty space, similar to a pumice stone on Earth.  The odd shapes of the craters are thought to be a result of this.  When an impactor hits Hyperion, it blows the material...

Dawn Mosaic of Ceres Shows a Dark Cratered World

The Dawn space craft has finally begun its science phase after settling into a 13,500 Km orbit around the dark dwarf planet Ceres.  It took some manoeuvring to get it in the right spot, but now it has begun mapping the surface as it slowly orbits once every two weeks.  A lovely mosaic image from the space craft is the latest jaw-dropping picture of the former asteroid. Like a great shot of the Lunar terminator, by seeing the shadows created by the light from the Sun, we can get a sense of depth of the heavy craters on the surface....

Cool Applet showing the surface of Vesta

Over the past few years, before heading to Ceres in a landmark rendezvous in March of 2015, the Dawn spacecraft mapped out the surface of the largest asteroid, Vesta.   This amazing little applet shows the entire surface of the asteroid with some craters highlighted.  Called Vestatrek, it shows all kinds of data from Dawn, including a 3D model of Vesta.  Definitely worth the time to geek out. http://vestatrek.jpl.nasa.gov/