Mars Phoenix from MRO

As you may be able to guess from the lack of posts over the past couple of weeks, I've been pretty busy with work. Yesterday Mars Phoenix landed and the first images have been blogged by Emily, Rob, Ian, Will, Chris and others around the web. This evening (UK time) the Mars Reconnaissance Orbiter team have released a great image of Mars Phoenix taken during descent.

Mars Phoenix
Phoenix Makes a Grand Entrance CREDIT: Mars Reconnaissance Orbiter Team
In the image you can see Mars Phoenix with its parachute open behind it. The Mars Reconnaissance Orbiter team were able to take the image because the camera was pointing in the same direction as the high-gain antenna.

The lander is in the north polar region of Mars so there will come a time when there won't be enough sunlight for the solar panels to generate enough power. At that point when "Mars freezes over" (in the words of one of the team) Phoenix will stop working. The Phoenix team reckon the lifetime will be limited to between 150 and 170 sols (Martian days).

Over the next few days we might expect the HiRISE instrument to snap a shot of Phoenix on the surface and plenty more interesting images from the lander itself. Also check out the twitter feed for the latest updates.

Posted in astro blog by Stuart on Monday 26th May 2008 (19:39 BST) | Permalink

World Wide Telescope First Impressions

Update (14/5/2008): Be sure to also check out Dave P's and Ian Musgrave's reviews.

This morning I got news that Microsoft had finally released a "Spring Beta" edition of their World Wide Telescope. It is heralded as the Microsoft version of Google Sky and some have even been in tears when describing it. Does it live up to the hype? Here is my quick review after only a little bit of time to play with it.

The download and install was actually very painless with only the need to install Div X as a minor annoyance. It starts up fairly quickly and the interface is actually quite nice to look at although it could do with hiding the Windows blue title bar. Anyway, here is what it looks like.

Start screen
The start screen for the World Wide Telescope (with tabs hidden) CREDIT: Microsofts World Wide Telescope
At the top you can see the menu tabs. Initially these have further options beneath them but I put them on auto-hide to free up so screen real-estate. With the top and bottom information areas this probably doesn't make for a brilliant use of space on a wide-screen monitor. Anyway, you can see that we start at Right Ascension and Declination of zero. The orange lines show the constellation boundary of the currently selected constellation (i.e. where the screen centre is). The green line shows the ecliptic (plane of the solar system). As I've said the interface is fairly nice to look at although can be a little clunky to use.

Let's get into the more exciting parts of WWT namely the ability to show sky surveys from the entire electromagnetic spectrum. This is a feature I've long been wanting in Stellarium or Google Sky (Rob did hack the time slider to do that) and it is nice to see that WWT has been very comprehensive. You can choose from most of the major sky surveys that exist from radio wavelengths up to gamma rays. I'll illustrate it with a WMAP view of the cosmic microwave background.

WMAP data
Changing the sky imagery to WMAP (Cosmic Microwave Background) CREDIT: Microsofts World Wide Telescope
At this point I'll show the distortions that get introduced if you zoom out too much. This is true of all planetarium software but for projection geeks it might be interesting to see.

WMAP data
WMAP data zoomed out showing projection distortion CREDIT: Microsofts World Wide Telescope
Now, let's switch to the NRAO's VLA Sky Survey which is well known to radio astronomers. The view below shows one of the brightest (the Sun is the brightest) radio objects in the sky - Cassiopeia A. The crazy pattern around the central object is actually due to the diffraction pattern of the telescopes and are called sidelobes. They are of the same origin as rings and spikes seen in optical telescopes due to secondary reflectors and support legs. It is quite nice to see Cass A in radio in the context of the whole sky.

NVSS data
The NRAOs VLA Sky Survey data showing Cassiopeia A CREDIT: Microsofts World Wide Telescope
Another nice feature is the search tool. This lets you search the name resolver in Simbad. Type in something like "NGC 884" and it will find the position and take you there. The only complaint I have about moving between objects is that it zooms out fully, then pans, then zooms back in. It would be nice if they did what Google Earth does and pan and zoom simultaneously.

Simbad search
Search with the Simbad name resolver CREDIT: Microsofts World Wide Telescope

NGC 884
NGC 884 CREDIT: Microsofts World Wide Telescope
Another feature which is very much like NASA's World Wind and lately Google Earth is the ability to zoom, pan and rotate around other planets. As an example, here is Venus.

Venus CREDIT: Microsofts World Wide Telescope
There are other features such as overlays of HST, Chandra and Spitzer images too but I haven't had chance to explore those yet. You can also connect to your own telescope using ASCOM so there is the possibility to control your observations from WWT too. In summary:


  • Looks quite nice
  • Multi-wavelength all sky surveys
  • FITS download of images from the DSS
  • Simbad name resolver search
  • ASCOM control


  • When changing object from a zoomed in view it zooms fully out, moves position and then zooms in. It would be nice to smoothly combine the two like in Google Earth/Sky.
  • I think I've seen some strange projection effects looking at 2MASS data.
  • You can't get a full screen view without the menu bar and the top option tabs
  • (from Alasdair in the comments) The Mac version isn't really a Mac version but a Windows version running under boot camp.

Bugs and improvements I'd like to see

  • I get flickering of overlay boxes on my Windows XP machine.
  • There is a possibility of fading between wavelength views (like the option in the web-based Google Sky) but I can't get it to work.
  • When viewing the Sun it would be nice if it displayed a live image from SOHO (or STEREO).
  • Update (14/5/2008): In Ian's review he says that there are problems with display when setting your location in the southern hemisphere

Posted in astro blog by Stuart on Tuesday 13th May 2008 (18:03 BST) | Permalink

Mercury in the beam

One of the nice things about my job is working in international collaborations. Most of the time we work by email, Skype and the internet but with people spread across about 130 degrees of longitude that can be awkward. Sometimes you just need to meet up and work face-to-face. So on Tuesday - a day that felt like the start of summer - I travelled to Paris for a three day meeting.

As is becoming a tradition on my blog, I wanted to get an astronomical shot with a famous landmark whilst I had the opportunity. I've previously snapped Saturn from Piazza San Marco (St Mark's square) and Venus next to the Colloseum so it seemed fitting to get another of the planets with a famous Parisian landmark.

La Tour Eiffel, Mercury and the Moon
Mercury in the searchlight beam of La Tour Eiffel taken on 7th May 2008. Click for the larger version. CREDIT: Stuart
I took this image from my hotel room window on 7th May when Mercury and the Moon were quite close. The quality of my shot isn't brilliant, as I only had my cheap digital camera withme, but it does just pick up Mercury. In this particular shot Mercury is fairly easy to find. Start at the Eiffel Tower (La Tour Eiffel) over to the right-hand side of the image. These days it looks rather like a lighthouse with a rotating searchlight beam. If you follow the beam past the foreground office block you will see a little blob (brightened for the small version of the image so it can be seen). That little blob is Mercury and up to the top left is a slightly over-exposed crescent Moon.

To see hundreds of stunning images of the night sky pictured above famous landmarks all over the world, visit The World At Night website.

Posted in astro blog by Stuart on Friday 09th May 2008 (18:52 BST) | Permalink

Trouble with UNITs

It is nice when somewhere you know gets referenced in popular fiction. I broke into a smile when Jodrell Bank was mentioned by the Colonel from UNIT in this week's episode of Doctor Who - The Poison Sky. Apparently Jodrell Bank had detected a signal 5000 miles above the Earth. I have to say that I am slightly disappointed that UNIT don't use SI units.

In real life Jodrell Bank is a radio quiet zone - it listens rather than transmits - but it does occasionally get referenced in British sci-fi detecting (or failing to detect) aliens. Back in real life, searches for aliens have been carried out at Jodrell Bank for the SETI Institute. That is one of the reasons Jodrell Bank has been referred to as a "real-life Torchwood Institute".

Now, I must go work out how to get perl talking to my sonic screwdriver.

Posted in astro blog by Stuart on Saturday 03rd May 2008 (20:17 BST) | Permalink
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