The current estimated reentry window runs from the night of 31 March to the late evening of 1 April (in UTC time); this is highly variable. Today’s new forecast is a noticeable change from that of yesterday, and is due to solar activity. One of the main reasons why it is so difficult to make an accurate reentry predictions, even if just a few days in advance of an expected reentry, materialised during the last 24 hours. A high-speed stream of particles from the Sun, which was expected to reach Earth and influence our planet’s geomagnetic field, did, in fact, not have any effect, and calmer space weather around Earth and its atmosphere is now expected in the coming days. This means that the density of the upper atmosphere, through which Tiangong-1 is moving, did not increase as predicted (which would have dragged the spacecraft down sooner) and hence the ESA Space Debris Office has adjusted the predicted decay rate. This implies that the new (and still uncertain) reentry window has shifted to later in the day on 1 April.
Reentry will take place anywhere between 43ºN and 43ºS (see map here). Areas above or below these latitudes can be excluded. At no time will a precise time/location prediction from ESA be possible. This forecast was updated approximately weekly through to mid-March, and is now being updated every day.
