** UPDATE 9 p.m. CDT April 1: The U.S. Strategic Command’s Joint Force Space Component Command announced that Tiangong 1 reentered the atmosphere over the southern Pacific Ocean at about 7:16 p.m. CDT April 1.
No April Fools. The latest prediction calls for the doomed Chinese space station, Tiangong 1, to burn up in the atmosphere tomorrow April 1 at 1 p.m. CDT (18:01 UT) +/– 6 hours. Should it reenter at 1 p.m., it will fall into the Pacific Ocean about 1,000 miles off the coast of California, the same time my family and I will be enjoying an Easter ham and cheesy potatoes.
Assuming the prediction interval holds true, many U.S. and some European cities will be able to see its final pass across the sky tomorrow morning. I’d love to get up to look, but my city won’t get a pass. A few of the larger ones that will include Cleveland, Chicago, Boston and Denver. To find out if your city will get one last look before reentry, go to Heavens Above, select your location either by name or clicking on the map, then return to Home and click the Tiangong-1 link in the column on the left hand side of the page.
You’ll get a listing of passes — if you’re lucky — that includes the date April 1. Click on that date for a map showing the space station’s path with times listed alongside it. You’ll also see dates past April 1 which you can ignore unless Tiangong 1 defies predictions. If no April 1 pass is shown, then like me, you’re out of luck. The Chinese space station is currently orbiting Earth at an altitude of around 110 miles (175 km), less than half the height of the International Space Station (ISS). Even the ISS feels slight drag from air in its much higher orbit and must periodically fire thrusters to raise its altitude. Imagine the drag Tiangong 1 must be experiencing in comparison right now.
A lower orbit means it’s moving quite a bit faster across the sky, too. Those attempting to spot Tiangong 1 may only see it for a minute or less as it zips across the sky. Because pass times could change a little from what’s shown at Heavens Above, it would be wise to be out looking in the direction of the pass at least 10 minutes early. For the very latest updates, check Joseph Remis’ Twitter. He provides the latest “decay prediction,” the time of the final plunge.
A satellite or in this case a space station can safely orbit Earth down to about 62 miles (100 km). Below that, resistance from the atmosphere will snap off its solar panels, heat it up and ultimately tear the craft to pieces. I hope you’ll be one of the lucky ones to spot Tiangong 1 on one of its final orbits. Wave ”hi” for me, would you?
You can learn more about tracking satellites whether that’s the ISS, spy satellites or old Russian Cosmos rocket stages in my brand new book Wonders of the Night Sky You Must See Before You Die. Click the photo to go to Amazon to order a copy. My first book, Night Sky with the Naked Eye is also available.