China's defunct space station to crash in the months ahead
Meteorologist/Science Writer
Friday, October 20, 2017, 4:23 PM - China's disabled Tiangong-1 space station is expected to crash back to Earth sometime before April 2018, the Moon photobombs NASA's view of the Sun, and take a tour of Mars from the comfort of your home. It's What's Up In Space!
Crashing back to Earth
The Tiangong-1 space station was launched into orbit on September 29, 2011 as a test platform for the future of China's space program. During its time in service, it supported three missions - one robotic, Shenzhou 8, which performed a docking test one month after the station was deployed, and two crewed, Shenzhou 9 in March 2012 and Shenzhou 10 in June 2013.
Since June 25, 2013, Tiangong-1 has simply been orbiting the planet on its own, with no more visits from any spacecraft, crewed or otherwise, and as of March of 2016, China hasn't even been in contact with the station, as it has "ceased functioning."
Reduced to a 10 metre long, 8 metric ton piece of space debris, Tiangong-1's orbit has slowly but surely been decaying over the past 19 months, from a distance of over 380 km down to now less than 300 km above Earth's surface.
In a statement delivered to the United Nations back in May of 2017, China's Permanent Mission to the UN said that the spacecraft's orbit is "decaying at a daily rate of approximately 160 metres" and that its reentry into Earth's atmosphere "is expected between October 2017 and April 2018."
According to the SatView website, which tracks the orbits of spacecraft and space junk, from today, October 20, 2017, Tiangong-1 has 171 days before its re-entry. That would bring it crashing down to Earth on April 9, 2018.
This screen capture from SatView.org, taken at approximately 3:30 p.m. ET, Oct 20, 2017, shows Tiangong-1 over western Africa, and that the station has 171 days, 3 hours, 58 minutes and 29 seconds left before it crashes. Click or tap the image to go to SatView.org
Does the station actually have that long, and where will it actually come down?
There's no telling, right now.
"You really can’t steer these things," Harvard astrophysicist, Jonathan McDowell, told the Guardian last year. "Even a couple of days before it re-enters we probably won’t know better than six or seven hours, plus or minus, when it’s going to come down. Not knowing when it’s going to come down translates as not knowing where it’s going to come down."
McDowell noted that, with the station now below 300 km, it is dipping into a thicker part of the atmosphere each time it makes an orbit. This will cause the station to slow, and for its orbit to decay even faster. So, we may not have until April before someone, somewhere, sees Tiangong-1 streak across the sky.
China officials have said that there is no danger from the station's impending breakup, however there are some larger portions of the station, which are made of denser materials, which could survive all the way to the ground.
More on this as updates come in!
The Moon photobombs NASA pics of the Sun
NASA's Solar Dynamics Observatory, SDO for short, keeps an unblinking watch over the Sun for us, from space. Every once in awhile, though, something blocks the satellite's view, and this is exactly what happened on Thursday, October 19.
NASA SDO's 171 Angstrom view of the Sun, highlighting the many coronal loops protruding from the 'surface', catches the edge of the Moon passing across. Credit: NASA
SDO takes multiple images of the Sun every hour, in several different wavelengths of ultraviolet light. Each different wavelength of light allows us to observe a different feature of the Sun's 'surface' and atmosphere (the corona), so that we can learn more about our nearest star, and also to help protect us from solar flares and coronal mass ejections, which can have a damaging impact on our technologies.
To see more from SDO, head to NASA's website.
Tour Mars from home!
It's looking like it's going to be at least another decade before we see humans walking around on the surface of Mars, but in the mean time, how about a way to tour it from the safety of your own living room?
Watch below: Take a trip to Mars with no airfare attached, here's how
The simulation takes images from the Mars Curiosity rover, and plots them onto a 3D environment. This does produce some limitations. If you stick to the views from the locations that Curiosity snapped the images, the terrain looks correct. If you venture away from those vantage points, however, the details of the view can look distorted, or details will be missing due to something that was impeding Curiosity's view of that particular part of Mars.
It's still quite an interesting experience, though. Try it out!
Follow this link to start the experience, on PC or mobile device, and apparently it's even better if you have a virtual reality headset!
Sources: CBC | The Guardian | NASA | NASA JPL
