Buzzing the Moon
NASA’s twin GRAIL spacecraft, Ebb and Flow, crashed into the Moon recently. Their fuel was exhausted, their mission to map lunar gravity complete. Fare thee well, fine ships. The video above is a view of their final days, skimming a mere 6 miles above the gorgeous lunar surface. I’m jealous.
"You are go for fly-by, GRAIL. The pattern is not full."
The two spacecraft orbited our rocky satellite, one lagging behind the other, sensing slight fluctuations in each other’s orbits caused by slight differences in the Moon’s gravity. For instance one passed over a spot with slightly stronger pull, it would dip ever so slightly. Communicating via microwaves, the other spacecraft would sense that dip. And so they flew, bobbing and weaving and mapping.
Technically, the Earth and the Moon aren’t perfect spheres. However, for all intents and purposes we can pretend they are, as they are certainly more perfectly round than a billiard ball. The Earth actually bulges slightly in the middle from the tug of the Moon’s gravity, like a tectonic high tide.
We know that everything with mass exerts gravity. Even the coffee cup currently next to me is pulling me toward it, and I’m pulling it toward me, however infinitesimally imperceptible that pull may be. Actually, that tug might be because I need coffee, but you get the idea. What most people don’t realize is that objects like the Earth and Moon don’t have evenly distributed mass, and likewise don’t have completely even gravity.
Everywhere on the Moon that there’s slightly denser, heavier rock, there’s slightly more gravity exerted above that spot. The GRAIL mission mapped the Moon’s blips and bulges in the greatest detail ever, giving us this abstract-art-like map:
If you want to read more about Earth’s lumpy gravity, check out this post by Phil Plait.
111 Notes/ Hide
- lunostar reblogged this from jtotheizzoe
- rachelinha reblogged this from thestarsbeckon
- experiencinghumanity reblogged this from jtotheizzoe
- datahacker likes this
- thestarsbeckon reblogged this from jtotheizzoe
- fluffypythoncupcakes reblogged this from jtotheizzoe
- theparadigm reblogged this from jtotheizzoe
- sameoldantics reblogged this from jtotheizzoe
- gottagotospace likes this
- leonerdnimoy reblogged this from jtotheizzoe
- ixchelnaom reblogged this from jtotheizzoe
- ixchelnaom likes this
- theparadigm likes this
- vdevinganca likes this
- anneisagoat reblogged this from jtotheizzoe
- zeekay likes this
- octagonperfectionist likes this
- kogonewsradio600 likes this
- maxim1959 reblogged this from jtotheizzoe
- appreciatetheair likes this
- weallcrazyhere reblogged this from jtotheizzoe
- allthethundermagazine likes this
- thecirclemustbebroken reblogged this from jtotheizzoe
- srikard likes this
- meechellelin likes this
- wineslacker likes this
- dullscythe likes this
- onehundredbilliongalaxies said: more smooth, NOT more round! CLICK THROUGH.
- moodindigo14 likes this
- tinydeath likes this
- petitegaylad said: Amazing!
- petitegaylad reblogged this from jtotheizzoe
- petitegaylad likes this
- greendalevulcanbeing likes this
- olumej likes this
- providentsparrow reblogged this from jtotheizzoe
- grumblebucket likes this
- violent-colors-so-obscene likes this
- jasonallensims reblogged this from jtotheizzoe
- danielladelarue likes this
- wordsarebutasthoughts likes this
- li-celly reblogged this from kyricns
- li-celly likes this
- ladybonerz likes this
- ihavenocoolname reblogged this from jtotheizzoe
- ifitistobeitisuptome11 reblogged this from jtotheizzoe
- whenmagiccomesalive reblogged this from jtotheizzoe
- jetpackcity likes this
- beenposh said: oh come on nasa, show us the crash!!!
- willonthebus reblogged this from jtotheizzoe