Looking over Enceladus

This stunning picture taken by the Cassini spacecraft was tweeted yesterday by Carolyn Porco, the leader of the Cassini imaging team, and I thought I’d share it here. Taken late last year, the image shows a close-up of Saturn’s moon Enceladus, with Saturn’s rings visible in the background. More info is given in the official caption at Cassini imaging hub Ciclops:

Cassini looks over cratered and tectonically deformed terrain on Saturn’s moon Enceladus as the camera also catches a glimpse of the planet’s rings in the background of this image from the spacecraft’s flyby of the moon on Nov. 30, 2010. Geologically young terrain in the middle latitudes of the moon gives way to older, cratered terrain in the northern latitudes. See PIA11685 to learn more. This view is centered on terrain at 41 degrees north latitude, 202 degrees west longitude. North on Enceladus (504 kilometers, 313 miles across) is up and rotated 28 degrees to the right. This view looks toward the northern, sunlit side of the rings from less than a degree above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 46,000 kilometers (29,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 14 degrees. Image scale is 276 meters (905 feet) per pixel.

Nice!

Image credit: NASA/JPL/Space Science Institute

An immigrant exoplanet

La Silla Observatory (Iztok Boncina/ESO)

ResearchBlogging.orgIt seems like every month a new kind of member is added to the ever growing exoplanet family: bigger, more massive, closer, brighter, hotter, rockier. The latest one, discovered by colleagues at my new institute, the Max Planck Institute for Astronomy in Heidelberg, is kind of special: it’s thought to have formed in another galaxy.

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CDS Portal

screenshot of the CDS portal

CDS, the Centre de Données Astronomiques de Strasbourg, already bring us the astronomy research goodness of Simbad, Vizier and Aladin. A month ago, the service launched a one-stop portal for all three services – I’ve been using it this week and it’s a great step forward.

The portal provides just one entry box for an object name or coordinates, and searches within a 2 arcmin standard radius for objects and bibliographic references via Simbad, images via Aladin and catalogues via Vizier. It’s obviously a first implementation, and the input options aren’t as rich as the full interface for each of the services (e.g. different coordinate systems, search radii), but this does provide a much cleaner, simpler look and feel. There’s even an experimental mobile interface, good for those who want to work on the go.

Interestingly, the CDS Portal contains a personalised “My Data” space, where you can import VO tables of objects as input for queries and store up to 500 MB of data for future use. This still looks a bit bare-bones for now but may well be the most promising new feature.

After the introduction of annotations in Simbad, the Portal and data space looks like another step in CDS’ evolution from a static database query service to an kind of integrated and personalised online workspace for astronomy. I’m interested in finding out what other new developments are in the works – and I have a feeling we’ll be hearing something about it at next year’s dotAstronomy…..

CDS’s developer for the Portal sent me a nice tweet inviting feedback and comments – I’m going to take the liberty to extend that invitation to all of you. Post comments on here or contact him via twitter.

Timescapes: Rapture

via astropixie:

tom lowe has been traveling around the southwestern part of the US for the last many months (a year almost?) with a huge haul of equipment to record timelapse shots for his upcoming feature film, timescapes, to be released next year.

his past work was gorgeous, but the production footage below shows that he is really revolutionizing this technique. i absolutely love the scenes that follow in the frame of our milky way galaxy across the sky, showing the earth in the foreground moving past. i’ve never seen the universe filmed in such a way. stunning work!

I like Lowe’s tagline on Vimeo: “somewhere worshipping T Malick”

TimeScapes: Rapture from Tom Lowe @ Timescapes on Vimeo.

Scientific hubris, or: Everything you thought you knew about straight line fits is wrong

ResearchBlogging.orgThink you’ve got your least squares down to a tee? Think again.

In a paper posted to the Arxiv in late August, David Hogg of NYU and his collaborators take us to task on our sloppy data fitting habits. And he’s not in the mood to mince his words.

It is conventional to begin any scientific document with an introduction that explains why the subject matter is important. Let us break with tradition and observe that in almost all cases in which scientists fit a straight line to their data, they are doing something that is simultaneously wrong and unnecessary.

Hear that? Next time you fit a straight line to your data, consider that you’re probably wasting your time. Stop pandering to style to get a “catchy punchline and compact, approximate representations”.

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