from the it-was-there,-hiding,-all-the-time dept.
The Lunar and Planetary Science Conference announced on 2015-03-16 that a 198 km wide crater has been found on the moon using the GRAIL spacecraft that uses gravitational field mapping. This enabled the discovery of craters below the surface. It's been named the Earhart crater. Nice gravitational photos can be found in the links.
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A NASA and German Aerospace Center mission using two spacecraft to map the strength of Earth's gravitational field has come to an end:
The Gravity Recovery and Climate Experiment (GRACE) mission has come to an end after more than 15 years in Earth orbit. The twin satellites chronicled the changes of the Earth's water, ice, and land since the spacecraft were launched from the Plesetsk Cosmodrome on March 17, 2002, on a mission that was originally only slated to last some five years. More than a decade after that, GRACE was still beaming data back to Earth when a technical issued forced mission planners to close out the program.
Similar in some aspects to other missions launched, GRACE made precise measurements via the two spacecraft – GRACE-1 and GRACE-2 – that comprised the mission. For GRACE's overall scientific objectives to be achieved the two satellites both had to be fully functional. However, this past September (2017), GRACE-2 encountered a battery issue that made it clear by mid-October that the battery would not allow scientists to operate its science instruments and telemetry transmitter. It was decided to decommission GRACE-2 and, in so doing, end GRACE's scientific mission.
[...] GRACE helped detail how our home world's changing seasons move water, ice, and even land (as a result of surface water mass changes) across the planet's surface, providing researchers with a better understanding of what drives the motion of these substances. Earth's climate, earthquakes, and our own activities all play their part in shaping the face of our world and GRACE provided insights into the dynamics of this change.
(Score: 2) by ikanreed on Friday March 20 2015, @01:43PM
They don't make it clear how that compares to other craters, but it seems like if it were visible, 198 kilometers would be relatively small compared to some of the craters on the near side of the moon that you can see from earth. There are many that are quite visible to the naked eye.
(Score: 5, Informative) by isostatic on Friday March 20 2015, @02:16PM
Largest crater is about 290km across, but you might be thinking of the seas that are visible.
20/20 vision gives you 1 minute of arc resolution, that's about 100km on the moon, so you should just about be able to pick out the largest craters, but they'd be very small, same size seeing a small mobile phone at the other end of a football stadium.
The Luna mares are 1,100 km, so 4 times the size, and somewhere in the region of seeing a large dinner plate at the other end of a football stadium.
(Score: 2) by ikanreed on Friday March 20 2015, @03:52PM
Thank you. That's helpful.
I just assumed the seas were craters.
(Score: 0) by Anonymous Coward on Friday March 20 2015, @11:09PM
you can see heaps of craters with a fairly cheap refractive telescope. if you have decent vision you might even be able to see a few with a pair of binoculars
reflective telescopes are the shit though. if you have one of those, i'm jealous... even moreso if you live away from cities where light pollution allows you to see more stuff
(Score: 2) by Thexalon on Friday March 20 2015, @04:34PM
Also, I'd think that "massive" would be precisely the wrong word to use when describing a feature whose defining characteristic is having an unusual lack of mass compared to the areas around it.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 2) by NotSanguine on Saturday March 21 2015, @03:04AM
Also, I'd think that "massive" would be precisely the wrong word to use when describing a feature whose defining characteristic is having an unusual lack of mass compared to the areas around it.
Not everyone thinks like a scientist. In general usage, massive does not just mean 'high mass'.
mas·sive [google.com]
ˈmasiv/
adjective
adjective: massive
2. exceptionally large.
"massive crowds are expected"
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 2) by Nuke on Friday March 20 2015, @02:12PM
The missing aviator? Why is it named after her - is it her crash site?
(Score: 1, Funny) by Anonymous Coward on Friday March 20 2015, @02:42PM
Earth females were complaining that all the other craters were named after earth men. Meanwhile, extra-terrestrials are organizing protests and riots on Earth because we named everything after Earthlings.
(Score: 3, Informative) by isostatic on Friday March 20 2015, @03:09PM
She was a pioneer. Charles Lindbergh has a crater too, as well as people that had nothing to do with that field, Charles Babbage for example, or Charles Darwin -- that's 120km large!
Near-side craters were obviously named after people in past centuries a long time ago, when the first telescopes were being made. Far side craters, as far as mankind was concerned, didn't exist until 1959. Fortunately new surface craters of any appreciable size are not found on the moon any more (insignificant ones measured in a few dozen metres are findable, but they don't really get named)
Ironically Neil Armstrong, Buzz Aldrin and Michael Collins got craters named after them, but they're all very small (2.4 - 4.6km in diameter).
(Score: 4, Touché) by MrGuy on Friday March 20 2015, @03:14PM
A crater can't be "massive." I am literally being pedantic right now.
How much dirt is there in a hole 10 feet wide, 10 feet long, and 10 feet deep?
(Score: 2) by GreatAuntAnesthesia on Friday March 20 2015, @03:29PM
Touché indeed. I wonder if there should be both "+1 pedantic" and "-1 pedantic" mod options.
(Score: 1) by rondon on Friday March 20 2015, @03:35PM
1,000 cubic feet minus the volume of the body at the bottom, I presume. ;)
Why else would you dig that hole in the first place?
(Score: 3, Informative) by bob_super on Friday March 20 2015, @04:20PM
If you have an atmosphere, you could argue that the amount of air contained inside the crater is massive.
But in this case you're wrong, because TFS is about a crater below the surface. So its content is massive.
(Score: 3, Insightful) by DeathMonkey on Friday March 20 2015, @05:35PM
Can a Canyon not be Grand, then?
(Score: 2) by tathra on Friday March 20 2015, @10:27PM
its the absolute value of the mass that's missing due to the fact that there's a crater/hole there (since the mass is missing we give it a negative, then use the absolute value since there's no such thing as negative mass).
(Score: 4, Touché) by wonkey_monkey on Friday March 20 2015, @11:03PM
I am literally being pedantic right now.
I think you mean "at the time of writing."
Unless you're also being pedantic now. Which you probably are.
systemd is Roko's Basilisk
(Score: 1) by KiloByte on Saturday March 21 2015, @12:29AM
The word "massive" doesn't imply "mass", they merely share etymology. In fact, out of four definitions given by WordNet, only one speaks of mass at all -- the other ones being "imposing in size/bulk", "solid", "imposing in scale/scope/degree/power". The crater isn't solid either, but two other definitions apply to it just fine.
Ceterum censeo systemd esse delendam.
(Score: 1, Informative) by Anonymous Coward on Friday March 20 2015, @05:06PM
Doesn't the word "photo", quite literally, imply the involvement of light? "Gravitational images" would be more appropriate.
(Score: 0) by Anonymous Coward on Friday March 20 2015, @08:34PM
At last, we've found the Monolith.