Whenever there’s news of an asteroid expected to pass closely by Earth (like this one did on Halloween 2015) at least one person will typically ask “what if it hit the Moon?” (as if that’s a scenario that somehow all of the astronomers around the world who specialize in near-Earth asteroids failed to take into consideration.) I assume the expected answer would be that such an impact would offset our Moon’s oh-so-delicate position in Earth orbit and send it tumbling inwards toward an inevitable and catastrophic collision with our planet, or possibly shatter it apart completely.
As it turns out the Moon is a lot tougher than many people think. (Maybe they’d just watched too many Saturday morning cartoons.)
On Nov. 11, 2015, NASA’s Cassini spacecraft passed relatively closely by Saturn’s moon Tethys, one of the ringed planet’s larger icy satellites. The animation above was made from 29 raw images acquired with Cassini’s narrow-angle camera as it passed by; you can see part of the incredibly cratered and ancient surface of this 662 mile (1,065 km) wide moon. Talk about flyover country!
For decades, far-off Pluto and its moons were just a collection of bright spots in even our most powerful telescopes. Now the dwarf planet and its family of five moons has been revealed in intimate detail with the long-awaited flyby of the New Horizons spacecraft.
Last week the “family portrait” of the Pluto system was made complete when our best close-up arrived of Kerberos, a tiny 7-mile-wide moon that nobody even knew about until 2011. And surprise: it looks like a contact binary!
On Wednesday, Oct. 14 2015, Cassini performed its scheduled “E-20” close pass of Enceladus, a 320-mile-wide moon of Saturn that is now famous for the organics-laden ice geysers that fire from cracks in its southern crust. E-20 is the first of a series of three flybys to be performed before the end of 2015, specifically timed to give the spacecraft a good view of Enceladus’ north polar region now that Saturn is moving into its summer season.
The raw image data from E-20 has just arrived on Earth today (which, by the way, is the 18th anniversary of Cassini’s launch!) and I particularly liked the one above. Crescent-lit by the Sun, Enceladus’ night side is seen bathed in the dimmer glow of reflected light off Saturn and its rings. Dead-center is the 6.5-mile-wide crater Bahman, surrounded by a wrinkly field of cracks and troughs in the moon’s highly-reflective icy surface.
This has made quite a splash across the internet over the past several weeks, and for good reason: the Project Apollo Archive is now on Flickr, giving anyone and everyone point-and-click access to some of the best scans of original Apollo mission photographs that have been made to date. Really, this is something you can get yourself wonderfully lost in (and I speak from personal experience!)