UPDATE 3: ROSAT Reentry Predicted for Today or Tomorrow

UPDATE 3: Latest from DLR (as of 10:00 pm EDT) is that ROSAT will renter any time now (or has already) between 0:30 GMT (which has passed) and 03:30 GMT (11:30 pm EDT). DLR (@DLR_en) tweeted that it will not reenter over Europe, Africa or Australia. USSTRATCOM says 02:04 GMT (10:04 pm EDT) plus or minus 2 hours.

UPDATE 2: Latest from DLR: between 23:30 UTC (7:30 pm EDT) today, Saturday, and 05:00 UTC (1:00 am EDT) tomorrow, Sunday. DLR (@DLR_en)tweets that “taking into account the most recent data, ROSAT will not reenter over Europe.”

UPDATE: Latest prediction from U.S. Strategic Command via the Space-Track website is October 23, 02:34:00 GMT (October 22, 10:34 pm EDT) plus or minus 7 hours.

ORIGINAL STORY: The latest predictions of when Germany’s ROSAT x-ray astronomy satellite will reenter show it will happen sometime today or tomorrow (Saturday-Sunday, October 22-23).

The U.S. government’s latest prediction at Space-Track shows the reentry period on October 23 at 01:31:00 GMT plus or minus 14 hours. That’s tonight, October 22, at 9:30 pm EDT. With a window of plus or minus 14 hours, that could make reentry anytime between right now and 11:30 am tomorrow EDT.

The German Aerospace Center’s (DLRs) website says it will reenter between October 22 at 18:00 UTC (which is the same as GMT) and October 23 at 12:00 UTC. That would be between this afternoon at 2:00 pm EDT and tomorrow morning at 8:00 am EDT.

The chances are extremely small that any one individual — you — would be hit by the debris, especially since the Earth is 70 percent covered with water, but there is a risk. The exact time and place of reentry cannot be predicted with precision. The major piece of ROSAT that is causing concern is its 1.7 metric ton main mirror, which is expected to survive the heat of reentry intact, unlike most satellite reentries where the spacecraft breaks up into many small pieces.

ROSAT does not have a propulsion system, so its path is dependent on natural forces.