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The Peregrine lunar lander left the Earth yesterday on the first launch of a Vulcan Centaur but it has suffered a serious problem and a propellant leak means that it won’t be able to land on the Moon. It is currently around 240,000 km away in Taurus and well placed for observation from the UK. You can get an ephemeris from JPL Horizons. I imaged it tonight (Jan 9) and it is currently around mag 17 and around 5 arcmin south of the predicted position.
Gennady Borisov has found the Centaur too and this was briefly listed as gb00471 on the NEOCP. I’ve just imaged it and it is around 12 deg SW of the spacecraft and quite a bit brighter at 14th mag.
When I imaged it there didn’t seem to be any tumbling.
That may change of course.
If it cannot land, will it stay in this orbit? Is it stable?
The lander trajectory is being significantly affected by the propellant leak. My astrometry of it tonight (Jan 10) is around 2 arcmins from where it should be assuming a ballistic trajectory. The spacecraft is around mag 18 tonight. The Centaur is much better behaved and quite bright (mag 14). We should be able to follow that for quite some time as it goes off in a heliocentric orbit. I’ve attached an ephemeris for the Centaur in case you want to have a go.
Alas, work got in the way last night. If Peregrine is 18th I probably won’t get it again until it loops back – if the JPL orbit is updated,,,,
Just imaged the lander and the Centaur and they are both close to the position predicted by Bill Gray’s site (https://projectpluto.com/sat_eph.htm). The Centaur (2024-006B) is around 17.0 now and the lander (2024-006A) is around 17.6. Astrobotic have said that the mission will end when the lander burns up at the next perigee on January 18.
Using astrometry from me (970), Peter Birtwhistle (J95) and Patrick Wiggins (718) obtained since the propellant leak stopped I get a nice fit (3-day arc, 0″.2 residuals) to a gravitational only orbit for the lander using Findorb. This gives a predicted Earth impact time of 23:44 UTC on 2024-01-18 over northern Australia in daylight. The lander is potentially imageable from the UK a few hours before re-entry on the night of the 18th as it moves through Cancer, low down in the east after sunset, although it will be moving very rapidly across the sky.
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