After voyaging 2.4 billion miles through space, NASA’s Dawn spacecraft is finally in the home stretch of its journey to Ceres, the largest member of the asteroid belt and one of five dwarf planets in the solar system.
Dawn was launched in 2007 to study two very different asteroids and learn more about the building blocks of our solar system. Ceres is Dawn’s second stop; its first was Vesta, which the spacecraft circled from July 2011 to September 2012.
Now, after leaving Vesta and traveling through space for more than two years, the spacecraft is roughly 400,000 miles away from Ceres and heading toward it at about 450 mph, with a rendezvous set for March 6.
Ancient fish eyes show rods, cones
Scientists have discovered a fossilized fish so well preserved that the rods and cones in its 300-million-year-old eyeballs are still visible under a scanning electron microscope.
It is the first time that fossilized photoreceptors from a vertebrate eye have ever been found, according to a paper published in Nature Communications. The researchers say the discovery also suggests that fish have been seeing the world in color for at least 300 million years.
Dwarf galaxy found nearby
Astronomers searching the sky with NASA’s Hubble Space Telescope have discovered an odd little dwarf galaxy right in our back yard — a mere 7 million light years away.
The findings, described in the Monthly Notices of the Royal Astronomical Society, add a new member to the more than 50 galaxies in our Local Group (part of the Laniakea supercluster), which includes Andromeda and our own Milky Way.
Most of the stars in the tiny galaxy known as KKs3 are old and dim, making it a fascinating fossil that could help astronomers understand what ancient galactic environments looked like.
Carrying just 23 million solar masses’ worth of star-stuff, KKs3 holds just one-10,000th of the stellar mass of the Milky Way. As a dwarf spheroidal galaxy, it lacks any distinctive spiral arms.