Twin NASA satellites are due for a cosmic collision of sorts after concluding a 15-month mission to map the gravity signature of Earth’s nearest neighbor.
Scientists last week set the Grail spacecraft, named Ebb and Flow, respectively, on course for a crash-landing into a lunar crater near the moon’s north pole.
But don’t expect to see any sky-borne flashes, as Ebb and Flow are, as one researcher put it, ‘washer-and-dryer-size spacecraft with empty fuel tanks.’
Twin NASA satellites ‘Ebb’ and ‘Flow’ are expected to plunge into a lunar on the moon’s north pole at 5:28 p.m. Monday
An artist’s depiction of the twin spacecraft (Ebb and Flow) that comprise NASA’s Gravity Recovery And Interior Laboratory (GRAIL) mission.
‘We’re not expecting a flash that is visible from Earth,’ Grail Principal Investigator Maria Zuber told Space.com.
The two satellites are reportedly about to run out of fuel, and were guided to the location to avoid an estimated 1-in-8 million chance they could plunge into a historically important part of the moon, like where the Apollo astronauts landed.
The $496 million Grail mission – short for Gravity Recovery and Interior Laboratory – launched in September 2011, and Ebb and Flow reportedly arrived in lunar orbit about three months later.
They are scheduled to hurtle into the crater at 3,760 miles-per-hour 20 seconds apart at 5:28 p.m. mission team members told Space.com.
‘They’re going to be completely blown apart,’ Grail mission manager David Lehman of NASA’s Jet Propulsion Laboratory in Pasadena, Calif reportedly said.
Added Zuber: ‘This is all according to plan.’
The $496 million Grail mission — short for Gravity Recovery and Interior Laboratory — launched in September 2011, and Ebb and Flow reportedly arrived in lunar orbit about three months later.
Grail’s primary science mission ran from March to May, during which the spacecraft zipped around the moon at an average altitude of 34 miles. Ebb and Flow dropped down to about 14 miles above the moon for an extended phase.
And the mission was – by all accounts – a success.
‘Grail has produced the highest-resolution, highest-quality gravity field for any planet in the solar system, including Earth,’ Zuber reportedly said.
The resulting map has revealed an incredibly pulverized lunar crust, Zuber added, suggesting that the moon, Earth, Mars, Mercury and Venus were pounded by long-ago impacts far more violently than previously thought.
Mission managers on Friday turned off Ebb and Flow’s science instruments and ordered a maneuver putting them on course for the rim of the crater, which reportedly sits at a latitude of 75.62 degrees north and a longitude of 26.63 degrees east.
The map shows the region where the twin spacecraft of NASA’s Gravity Recovery and Interior Laboratory mission will impact on Monday
The map created by Ebb and Flow has revealed an incredibly pulverized lunar crust, suggesting the moon, Earth, Mars, Mercury and Venus were pounded by long-ago impacts far more violently than previously thought. ‘Grail has produced the highest-resolution, highest-quality gravity field for any planet in the solar system, including Earth.’
The violent demise of Ebb and Flow should provide mission scientists with information about the properties of the crater rim, perhaps shedding further light on lunar composition, according to Space.com.
It’s also possible the probes’ impact will expel water ice or other volatiles into the wispy lunar atmosphere, where they can be detected by NASA’s Lunar Reconnaissance Orbiter.
This locations on the moon that NASA considers ‘lunar heritage sites’ and the path GRAIL will take to avoid hitting any of them
These 3D renderings show the lunar mountain targeted by the GRAIL mission for controlled impact of the Ebb and Flow spacecraft
Researchers reportedly said the LRO has been studying the crash site and will attempt to do so again during and after the impact.
But the Grail team doesn’t necessarily expect to see ice. The crater rim is in sunlight much of the time, and the spacecraft just aren’t big enough to kick up much stuff.
Using a precision formation-flying technique, the twin GRAIL spacecraft — Ebb and Flow — have mapped the Moon’s gravity field, as depicted in this artist’s rendering.
Attribution: Mike Jaccarino, Mail Online