Note: this is a repost of an article from Feb. 2015 with a couple of updates.
If any of you remember it back in Dec. 2010 Japan’s Venus Climate Orbiter spacecraft AKATSUKI (aka Planet-C), after a five and a half month journey through space, failed to enter orbit around Venus due to a faulty thruster nozzle. It sailed right past the cloud-covered planet, going into orbit around the Sun. Fortunately, JAXA mission engineers were able to determine the cause of the problem and come up with some work-arounds for a second — and final — attempt on Monday, Dec. 7.
In April of 1972 the penultimate Apollo mission sent NASA astronauts John Young and Charles Duke to the surface of the Moon, with Ken Mattingly piloting the command module Casper in lunar orbit. After launch on April 16, the Apollo 16 craft and crew completed two orbits of Earth before burning the J-2 engine of the Saturn V’s third stage, the S-IVB (“S four B”), sending the crew off to the Moon.
Following the CSM and LM separation and TLI the spent S-IVB third stage continued along its course for a planned impact of the lunar surface. This was done as part of seismic experiments which collected data on lunar geology via surface instruments set up during previous missions. The 12-ton Apollo 16 rocket stage struck the Moon on April 19, a day and a half before the LM Orion touched down in the Descartes Highlands. But because the tracking signal was lost before impact it’s never been known exactly where the Apollo 16 S-IVB impact site was located.
That is, until now. After 43 years, one researcher at the Johns Hopkins University Applied Physics Laboratory has identified the crater left by the Apollo 16 third stage in image data gathered by NASA’s Lunar Reconnaissance Orbiter.
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.)
Now over four months after the historic and long-awaited flyby of Pluto by New Horizons, planetary scientists have had a steady stream of unprecedented data arriving on Earth from the outwardly-speeding spacecraft. We’ve learned more about Pluto in the past few months than we had over the decades before and the information is still being analyzed — and is still coming. This surprising little world and its strange family of mismatched moons, 33 times farther from the Sun than us, has become in the latter half of 2015 the scientific “star of the Solar System.” (Take that all you can’t-be-a-planet folks!)
“It’s hard to imagine how rapidly our view of Pluto and its moons are evolving as new data stream in each week. As the discoveries pour in from those data, Pluto is becoming a star of the Solar System. Moreover, I’d wager that for most planetary scientists, any one or two of our latest major findings on one world would be considered astounding. To have them all is simply incredible.”
– Dr. Alan Stern, New Horizons Principal Investigator, SwRI
Phobos, the largest — yet at just 16 miles wide still quite tiny — moon of Mars is getting ripped apart by the gravitational pull of its parent planet… and it bears the scars to show it, scientists have determined.
Long parallel grooves that wrap around the surface of Phobos are thought to be stress fractures — surface evidence of the tidal forces that will one day cause the moon to break apart entirely. This fate is not surprising to scientists, but that we’re seeing it in action is fascinating.
“We think that Phobos has already started to fail, and the first sign of this failure is the production of these grooves,” said Terry Hurford of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.