Coming this March – Reentry of Chinese Space Station

Its inevitable, what goes up must come down. On average there is one large piece of equipment that re-enters our atmosphere every week. Some are controlled and planned decommissioning of satellites after their useful life. They are purposely commanded for re-entry and burn-up in the atmosphere to avoid adding debris to our already crowded space orbits or worse, cause a collision with another satellite creating an enormous field of debris. Other objects that re-enter are left to fall on their own such as discarded rocket bodies and old satellite that ceased to operate long ago or malfunctioned and can no longer be controlled.

Tiangong-1 : First Chinese space station launched in 2011

Tiangong-1 : First Chinese space station launched in 2011

This coming March the 8,500kg (18,700lbs) Tiangong-1 Chinese space station is coming back to Earth. Launched in September 2011 and used for two manned missions, it suffered a malfunction and the Chinese have not been in control of it since 2016. The space station has been in a decaying orbit ever since, and now below the 300km altitude  where Earth’s atmosphere is causing the space station to slow down due to aerodynamic drag it will soon make its re-entry.

Delta 2 rocket fuel tank surviving re-entry near Georgetown, TX, on 22 January 1997

Delta 2 rocket fuel tank surviving re-entry near Georgetown, TX, on 22 January 1997

Now there is no need to panic. Most of Earth is ocean, and we’ll probably not see anything let alone have a piece of it land in a city. However as this is a fairly large body, there is a good chance  not all pieces will burn up and some may make it to the surface.

This isn’t the first time a space station makes a re-entry.  The American Skylab at 77 tons re-entered in 1979, and Russian Mir (120 tons) made its re-entry in 2001.
For the Mir re-entry, Taco Bell even got it onto the re-entry buzz by anchoring a large

Taco Bell target for Mir re-entry (2001)
Taco Bell target for Mir re-entry (2001)

target off the Australian coast along the planned re-entry track, and should Mir crash into it there would be free tacos for all Americans. The fast food chain even took out an insurance policy just in case it would happen.

In early January 2018, Tiangong-1 is orbiting at an altitude of around 270-290km (to put that into perspective, ISS is at a 400km orbit) and in a 45 deg orbit, hence the re-entry will be within those latitudes.  The green area in the map below is where Tiangong-1 could make a re-entry, and also marks where the re-entry could be observed.

Tiangong-1 ground coverage -

Tiangong-1 ground coverage –

It’s still too early to determine the time and location of potentially crash site, as Earth’s atmosphere is influenced by space weather and swells based on our Sun’s moods, which alters the drag force on the space station.  However various space centers and organizations will continue to track the space station the coming weeks to improve the prediction.

You can follow everything at for up to date information and predictions.

What could the re-entry look like?  Below is a video shot by NASA of the Japanese Hayabusa spacecraft during a controlled re-entry on June 13, 2010


Red Dwarf Spaceship Spotting?

The big news this week is the first recordings and observations of an interstellar object.  Of the 750,000 asteroids and comets that have been cataloged up to now, every one of them originate from within our solar system. This object detected by the Pan-STARRS1 telescope and named A/2017 U1 or “Oumuamua”, a Hawaiian word for scout or messenger from the distant past, came from another part of our galaxy. Based on measurements made from multiple ground-based telescopes it is believed to be rather long and of a deep red color . Below is an artist’s rendering of this extra-solar visitor. While a comet would have generated some type of coma or tail travelling near the Sun, no such activity was recorded, hence it’s believed to be an asteroid-type object.

Artist’s impression of the interstellar asteroid `Oumuamua

Credit: ESO/M. Kornmesser






Measurements over multiple nights allowed to establish the trajectory, which clearly shows that it did not originate from the Oort cloud or other asteroid/comet rich fields surrounding the Sun. While the discovery was made only on an October 19 image, its closest approach to the Sun was September 9th.


Diagram showing the trajectory of A/2017 U1 (ESO/K. Meech, et al.)

Now I thing they got it all wrong.  What they picked-up was the Red Dwarf mining ship swinging by our neighborhood!


Red Dwarf mining vessel owned by the Jupiter Mining Corporation (BBC)


ESO Press Release

My photo in this week’s SkyNews

Today I got an e-mail from Gary that a photo of the Big Dipper that I had submitted a few months ago got selected for this week’s column on SkyNews. Couldn’t be happier. I wish all my weeks could start this way.

My photo featured on SkyNews

Astrophotography is a combination of equipment, experience, location/timing and luck. With this photo I just happen to hit everything right and was lucky.

Using the best equipment helps, but for this photo it was the simplest of setup: my very worn Canon Rebel XTi DSLR with a zoom lens set to 17mm F4 mounted on an old steel camera tripod my father used in the 60s. So nothing special, and within everyone’s reach.

OK, for the next part I had experience on my side. It allowed me to pick the right camera settings, but was also lucky as my photo viewing was limited to that small LCD screen on the camera. I had no laptop to fully explore and review the photos and make the necessary adjustments.  Even the focus was reviewed through the small camera LCD.  That night I only took 4 images with 20 second exposure crossing my fingers that I would have something worthwhile once back home.

And then there is the post-processing on the computer, which is a lot of trial-error. In image processing doing steps A + B will not give you the same results as performing B + A. We all have our “recipes” for what produces good results, but every photo ends up being a unique project. With this one, I knew there was good potential.

Finally there is the location and timing.  I was up in cottage country, away from city lights, and a clear sky. However there was a full moon rising, couldn’t wait too long as the sky would start to brighten. A Big Dipper low in the sky next to the trees framed everything very well.

Thanks Gary and SkyNews for selecting my photo. For all the experimentation that I do with the camera, once in a while I get everything right. I’m just happy someone noticed and said “Hey, that’s a great photo we could use.”

Large Asteroid to Pass Near Earth

On April 19th a considerable sized asteroid will pass about 4.6 lunar distances (1.8 million km) from Earth.  While there is no chance of it impacting our planet, this 650m asteroid was only discovered three years ago, and it will be the closest encounter of a large asteroid since asteroid Toutatis in September 2004. The next predicted fly-by of a large asteroid is 2027 with 800m wide 1990 AN10.

The expected magnitude could reach up to 11 during the close approach, hence a decent sized scope will be required, and due to the rapid movement may be hard to locate and track.

Sky chart for asteroid 2014 JO25 covering April 18th to 20th 2017

And as a bonus, comet PanSTARRS (C/2015 ER61) will also make its closest approach to Earth on the 19th, but 10 times farther away as the asteroid.  I should be visible with small telescopes or binoculars in the constellation Aquarius in the dawn sky.

Source: NASA/JPL

Comets for 2017 [updated 16-APR-2017]

Below are some of the comets to keep a watch for in 2017 as they should be observable with small scopes and even binoculars.

Currently observable low in the evening at around magnitude 8 and will continue to brighten to magnitude 7 in January and then fade rapidly, including a approach to within 0.08AU of Earth on February 11th, as well as passing within a few degrees of globular cluster M3 shortly after.
  Photo from January 6th.

C/2016 U1 ( NEOWISE )
Currently observable at magnitude 9 and predicted to brighten to magnitude 7 in mid January.  Discovered on October 21, 2016.  Not visible in the southern hemisphere.

C/2015 V2 ( Johnson )
Faint at magnitude 12, and will continue to brighten until mid 2017, with good chances of observation.

C/2015 ER61 ( PanSTARRS )
Should brighten to magnitude 7 spring of 2017, unfortunately not very visible to the northern latitudes.  However it will cross many NGC and Messier objects throughout the first half of the year.

Expected to brighten to magnitude 6-7 around at the start of March, overall visible for about 45 days.  For those in the northern hemisphere, best observations will be the end of February.

Expected to brighten to better than magnitude 6 in early April.  A good opportunity for wide-field photo as it passes 5° of M92 at the end of April.
Photo from April 13th.

Comet Chasing
Seiichi Yoshida’s Bright Comet Listing (and future listing)
Paper by the British Astronomical Association

JunoCam – Revealing Jupiter from New Angles

JunoCam onboard the Juno spacecraft is providing us with some great pictures of the Jupiter cloud top, but from the rarely seen polar angle.  Pretty much all spacecrafts that have visited Jupiter did so with a fly by along the equatorial plane, which is also the same plane we observe Jupiter here on Earth.  However with the Juno spacecraft, we now have a chance to enter into a polar orbit and take pictures of the polar regions.

Part of the reason behind JunoCam is to get the amateur astronomer community participating in selecting what parts of Jupiter the camera should be snapping pictures, and of processing the raw images.  The image below was captured by JunoCam during Juno’s 3rd swing around Jupiter at a distance of about 37,000km.  The south polar region is on the left.

Jupiter - December 11, 2016 JunoCam - Juno Spacecraft

NASA, JPL-Caltech, SwRI, MSSS; Processing: Damian Peach

The above was the PeriJove3 encounter (3rd pass), and voting on the next PeriJove4 will take place between January 19th and 23rd 2017.  This is where the community can propose and vote for Points of Interest to photograph with JunoCam during the rather quick (2 hours) close pass with Juno.  You can even submit images of Jupiter taken with your equipment to help plan the Points of Interest.

Ref: JunoMission


TIME  magazine has released what their editors consider the best space photos of 2016.

P Crowther, University of Sheffield/NASA/ESA