All posts by Tom

VA223 Launch Replay

A replay of the 27 May 2015 launch of Ariane 5 Flight VA223 from the ESA Spaceport in French Guiana. The payload was the Skym-1 which was placed safely in orbit.

The Skym-1 satellite was built by Orbital Sciences in just 20 months and delivered to the launch site four months ahead of schedule.

Video credit: ESA/CNES/Arianespace – Optique Video du CSG

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Ceres Up Close


We’re starting to get great detail from Dawn and it’s going to get better. This image gets us to a resolution of about 480 meters (1,600 feet) per pixel.

The image was taken on 23 May 2015 from just 5,100 km (3,200 miles) away. According to the NASA view shows numerous secondary craters, those made by the debris excavated by larger impacts. The central part of the large crater is pretty interesting, the central peak appears to be a gouge.

The series of images producing this one is the last of the images produced for navigational purposes. If you are wondering about the black corner in the upper right, this image was projected on to a globe of Ceres.

The region shown here is located between 13 degrees and 51 degrees north latitude and 182 degrees and 228 degrees east longitude.

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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Mission to Europa

Tuesday there was a press conference to announce which of the 33 proposed for science instruments to fly aboard the Europa mission.

John Grunsfeld, associate administrator for the Science Mission Directorate, NASA Headquarters
Jim Green, director, Planetary Science Division, NASA Headquarters
Curt Niebur, Europa program scientist, NASA Headquarters


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Rhea’s Horizon


Seeing the icy moon Rhea up close is always a treat. This Cassini image shows us a very battered surface.

Being a moon of Saturn this is a very cold place, the surface temperature  ranges from about -220 C to -174 C on a warm day (-364 F to -281 F).  It will be fun to compare this to Pluto and its moons which we think is about -229 C (-380 C).

Image Credit: NASA/JPL-Caltech/Space Science Institute.

From the Cassini imaging team:

Gazing off toward the horizon is thought-provoking no matter what body’s horizon it is. Rhea’s horizon is slightly irregular and battered by craters, so thoughts inevitably turn towards the forces that shape these icy worlds.

The surface of Rhea (949 miles or 1527 kilometers across) has been sculpted largely by impact cratering, each crater a reminder of a collision sometime in the moon’s history. On more geologically active worlds like Earth, the craters would be erased by erosion, volcanoes or tectonics. But on quieter worlds like Rhea, the craters remain until they are disrupted or covered up by the ejecta of a subsequent impact.

Lit terrain seen here is on the trailing hemisphere of Rhea. North on Rhea is up and rotated 12 degrees to the right. In this view, Cassini was at a subspacecraft latitude of 9 degrees North. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 10, 2015.

The view was obtained at a distance of approximately 35,000 miles (56,000 kilometers) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 76 degrees. Image scale is 1,100 feet (330 meters) per pixel.

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A Rover’s Wheel


Here is an image of one of the wheels of the Mars rover Curiosity taken on Sol 995 (2015-05-25).

I’ve been watching the surprising amount of wear on the wheels of the rover since last year and I know the Mission Team is too. At least some of the drive planning has taken the wear into account.

As you can see the Martian terrain is tough on “tires”. The good part is the wheels don’t “appear” to be worn too much more than they were six months ago and they are not keeping Curiosity from doing great science. The next Mars rover, called the 2020 Rover (for its launch date) is based on Curiosity, I suspect there will be some changes to the wheels.

By the way: the 2020 Rover is still in the pre-planning stage, you can get an idea of what they are looking at by visiting here. Who knows, perhaps some engineering student reading this will be working on the project.

Image Credit: NASA/JPL-Caltech

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Hubble Update to NGC 6240


Here is an updated Hubble image of the galactic merger NGC 6240 (image description below) from an image in 2008. The image was taken with the Wide Field Camera 3 and Advanced Camera for Surveys which gives us a more detailed look at the center of the galaxies than in 2008. Click the image above to see the difference.

When I say galactic merger I don’t want to imply this merger is complete – far from it. What isn’t seen here are two black holes at the center of the merger only 3000 light-years apart and that is close enough for their fate to be set. The two black holes are feeling their mutual gravitational attraction and are slowly spiraling towards each other and will eventually merge into a single black hole.

We do have X-ray evidence of the two black holes in this image from the Chandra X-ray Observatory taken in 2002.

NGC 6240 is located 400 million light-years away in the constellation Ophiuchus, that is so far away, who knows perhaps the merger has already taken place, the cosmic look back time in action.

A side note: You would think there would be stars colliding in such mergers, but this is not the case. The distances between stars is so large such collisions are unlikely at least in any widespread way.

From Hubble (and you can get desktop versions of the image at the link):
Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown here in a pinky-red hue at the centre of the galaxies, was only revealed in these new observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys.

NGC 6240 lies 400 million light-years away in the constellation of Ophiuchus (The Serpent Holder). This galaxy has an elongated shape with branching wisps, loops and tails. This mess of gas, dust and stars bears more than a passing resemblance to a butterfly and, though perhaps less conventionally beautiful, a lobster.

This bizarrely-shaped galaxy did not begin its life looking like this; its distorted appearance is a result of a galactic merger that occurred when two galaxies drifted too close to one another. This merger sparked bursts of new star formation and triggered many hot young stars to explode as supernovae. A new supernova was discovered in this galaxy in 2013, named SN 2013dc. It is not visible in this image, but its location is indicated here.

At the centre of NGC 6240 an even more interesting phenomenon is taking place. When the two galaxies came together, their central black holes did so too. There are two supermassive black holes within this jumble, spiralling closer and closer to one another. They are currently only some 3000 light-years apart, incredibly close given that the galaxy itself spans 300 000 light-years. This proximity secures their fate as they are now too close to escape each other and will soon form a single immense black hole.

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Blue Origin

Here is the first flight of the New Shepard space vehicle from Blue Origin. The New Shepard was launched from the Blue Origin launch facility (probably Corn Ranch) near Van Horn Texas. The launch date was 29 April 2015.

A great looking launch sent the spacecraft to an altitude at 93.6 km / 307,000 feet on the first flight. It is a fine way to start, yet according to the news release from Blue Origin the New Shepard’s flight was not “perfect” because of a hydraulic pressure loss, the propulsion module could not be recovered. Don’t be so hard on yourselves, it’s just the first flight. Congrats Blue Origin!

Blue Origin is a privately funded aerospace manufacturer set up by Jeff Bezos ( This is just the first of many more flights from this company. In fact they are already building the Very Big Brother to New Shepard which is an orbital version.


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Supernova Animation

A nice animation of a Type 1a Supernova. The Type 1a isn’t a giant star exploding, rather it is a smaller white dwarf star pulling matter off a larger companion until the smaller star accumulates enough matter, around 1.44 solar masses, so the star can no longer support its weight with electron degeneracy pressure – that’s when things go bad.

A white dwarf star is what our Sun will become in the distant future. Since it does not have a binary companion it will not become a supernova, just a super-dense remnant.


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The Bright Spots of Ceres


The Dawn mission team has released two more images featuring one of the bright spot areas on the Dwarf Planet Ceres. They are getting more detailed all the time.

The images were taken on 16 May 2015 from a distance of 7,200 km / 4,500 miles.

The first of the two (above) is almost directly on and the second (click here) is more of an oblique view.

It will be interesting to see the topography measurements. The craters around the bright spots do appear to be shallower than in other areas. It could be just perception but in the oblique view there are more “bright areas” and it’s almost as if the surface layer depth is uneven across Ceres.

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

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The Medusa


Astronomers used the ESO’s Very large Telescope in Chile took this “most detailed” image of the Medusa Nebula.

The colorful nebula cloud is from the the central star that has puffed off its outer layers, just like our Sun will do far in the future.

This nebula is off the “knee” of Pollux in the Gemini constellation. The ESO team put out a wide-field view that is amazingly good and more inline with what you would see in a telescope although way-way better of course. (Credit: ESO/Digitized Sky Survey 2) It in my opinion pretty hard to see, at least it was for me and my scope.

Want a desktop of this image and much higher resolution images in general? Go here to visit the ESO page.

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