NGC 4102 and Hubble

Hubble's view of NGC 4102. Credit: ESA/Hubble, NASA and S. Smartt (Queen's University Belfast) Acknowledgement: Renaud Houdinet

Hubble’s view of NGC 4102. Credit: ESA/Hubble, NASA and S. Smartt (Queen’s University Belfast) Acknowledgement: Renaud Houdinet

Starting the week off is this very nice Hubble image of NGC 4102,  one of many objects in Ursa Major. This galaxy is viewable in the Northern Hemisphere with decently dark skies. Considering it is something in the order of 21 mega-parsecs away even a magnitude 11 is pretty good and this Hubble image – wow.

Ursa Major is a large constellation so here is a chart  to show the approximate location.

The original caption released with image:

The NASA/ESA Hubble Space Telescope observes some of the most beautiful galaxies in our skies — spirals sparkling with bright stellar nurseries, violent duos ripping gas and stars away from one another as they tangle together, and ethereal irregular galaxies that hang like flocks of birds suspended in the blackness of space.

However, galaxies, like humans, are not all supermodels. This little spiral, known as NGC 4102, has a different kind of appeal, with its tightly-wound spiral arms and understated, but charming, appearance.

NGC 4102 lies in the northern constellation of Ursa Major (The Great Bear). It contains what is known as a LINER, or low-ionization nuclear emission-line region, meaning that its nucleus emits particular types of radiation — specifically, emission from weakly-ionized or neutral atoms of certain elements. Even in this sense, NGC 4102 is not special; around one third of all nearby galaxies are thought to be LINER galaxies.

Many LINER galaxies also contain intense regions of star formation. This is thought to be intrinsically linked to their centers but just why, is still a mystery for astronomers — either the starbursts pour fuel inwards to fuel the LINERs, or this active central region triggers the starbursts. NGC 4102 does indeed contain a starburst region towards its center, where stars are being created at a rate much more furious than in a normal galaxy. This star formation is taking place within a small rotating disk, around 1000 light-years in diameter and with a mass some three billion times the mass of the sun.

This image uses infrared and visible observations taken using Hubble’s Wide Field Planetary Camera 2.

European Space Agency

3D Atlas of the Universe

A TED Talk. It isn’t  the solstice video I was intending to put up, but I liked it better.

Yes it’s a solstice day!

The December solstice is here. The solstice occurs in a few hours at 23:03 UTC. The calendar day would be 21 or 22 December depending on your location.

For me, it is the shortest day of the year and after a short pause the day’s  light will slowly lengthen.  The road to spring is long and as a well known old-time weather man around here used to say: “As the days grow longer the cold grows stronger”.

My favorite site for solstice information can be found at


Jupiter From Below

A Cassini view of Jupiter's southern hemisphere. Credit: NASA/JPL/Space Science Institute

A Cassini view of Jupiter’s southern hemisphere. Credit: NASA/JPL/Space Science Institute

Instead of Saturn, this Cassini image shows us Jupiter from a completely different perspective.  Yes there is a view from the north too it’s linked below.

No polar vortex is evident from this image.

From ESA’s Space in Images:

This Cassini image shows Jupiter from an unusual perspective. If you were to float just beneath the giant planet and look directly up, you would be greeted with this striking sight: red, bronze and white bands encircling a hazy south pole. The multicoloured concentric layers are broken in places by prominent weather systems such as Jupiter’s famous Great Red Spot, visible towards the upper left, chaotic patches of cloud and pale white dots. Many of these lighter patches contain lightning-filled thunderstorms.

Jupiter has very dramatic weather – the planet’s axis is not as tilted (towards or away from the Sun) as much as Earth’s so it does not have significant seasonal changes, but it does have a thick and tumultuous atmosphere filled with raging storms and chaotic cloud systems.
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Philae at Perihelion Cliff

Philae's look at its landing area. Image Credit: Copyright: ESA/Rosetta/Philae/CIVA

Philae’s look at its landing area. Image Credit: Copyright: ESA/Rosetta/Philae/CIVA

It be could be the location of ESA’s Philae lander on comet 67P/Churyumov-Gerasimenko has been narrowed down. The image above is from that location and we are looking at what has been named “Perihelion Cliff.”

The image was taken with the CIVA camera (Comet Infrared and Visible Analyser) on Philae.

To see a graphic showing the position of the Philae in the context of topographic modeling click here. (image credit as above via JPL)

Some of the first of the Rosetta results are being presented at the 2014 autumn meeting of the American Geophysical Union (AGU) going on right now in San Fransisco.

Rosetta will be doing a very close approach of the comet in February when it will come within 6.4 km / 4 miles of the surface.  I’m not sure where that will occur related to the location of Philae.

Knowing the location of Philae is would be a big relief.  I have not heard or seen specifically the location is known for certain, but we are closer to knowing than we were.

From JPL:

Rosetta is a European Space Agency mission with contributions from its member states and NASA. Rosetta’s Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the U.S. participation in the Rosetta mission for NASA’s Science Mission Directorate in Washington.

Goodbye Venus Express

Artists concept of Venus Express aerobraking. Credit: ESA

Artists concept of Venus Express aerobraking. Credit: ESA

Word comes from ESA the Venus Express mission has come to an end:

ESA’s Venus Express has ended its eight-year mission after far exceeding its planned life. The spacecraft exhausted its propellant during a series of thruster burns to raise its orbit following the low-altitude aerobraking earlier this year.

Since its arrival at Venus in 2006, Venus Express had been on an elliptical 24‑hour orbit, traveling 66 000 km above the south pole at its furthest point and to within 200 km over the north pole on its closest approach, conducting a detailed study of the planet and its atmosphere.

However, after eight years in orbit and with propellant for its propulsion system running low, Venus Express was tasked in mid-2014 with a daring aerobraking campaign, during which it dipped progressively lower into the atmosphere on its closest approaches to the planet.

Read the rest at ESA.

Moon Pairing

Cassini spies a pair of Saturn moons. Image Credit: NASA/JPL-Caltech/Space Science Institute

Cassini spies a pair of Saturn moons. Image Credit: NASA/JPL-Caltech/Space Science Institute

A very nice Cassini image of the Saturn moons Rhea and Tethys. The orientation of the pair is such that we can see what looks like large matching craters on each moon.  I believe the crater on Rhea (the moon in front) is Tirawa.  The crater is 360 km / 220 mile wide and makes up the Tirawa impact basin. The crater on Tethys is even larger, a true giant considering it is has a diameter 400 km / 249 miles or about 40 percent of the moons diameter.

From the Cassini site:

Tethys appears to be peeking out from behind Rhea, watching the watcher.

Scientists believe that Tethys’ surprisingly high albedo is due to the water ice jets emerging from its neighbor, Enceladus. The fresh water ice becomes the E ring and can eventually arrive at Tethys, giving it a fresh surface layer of clean ice.

Lit terrain seen here is on the anti-Saturn side of Rhea. North on Rhea is up. The image was taken in red light with the Cassini spacecraft narrow-angle camera on April 20, 2012.

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JUICE Gets Approval

Artist's impression of the JUICE mission. Credit: ESA/AOES

Artist’s impression of the JUICE mission. Credit: ESA/AOES

ESA has given the JUICE mission the go ahead to move to the next stage of implementation.

JUICE is the JUpiter ICy moons Explorer and will (hopefully) launch in 2022. The spacecraft will arrive at Jupiter in 2030 to study the giant planet’s atmosphere and magnetosphere, the rings, and the larger moons.

The moons to be studied are likely: Ganymede, Callisto, Europa, and Io. Io is a volcanic wonder and the other three might have internal liquid oceans and therefore could contain habitat for life.

From the ESA press release:

The scientific goals of the mission are enabled by its instrument suite. This includes cameras, spectrometers, a radar, an altimeter, radio science experiments and sensors used to monitor the plasma environment in the Jovian system. In February 2013, the SPC approved the payload that will be developed by scientific teams from 16 European countries, the USA and Japan, through corresponding national funding.
At the November 2014 meeting of the SPC, the multilateral agreement for JUICE was also approved. This agreement provides the legal framework for provision of payload equipment and ongoing mission support between funding agencies. The parties to the agreement are the European Space Agency and the funding agencies of the European countries leading the instrument developments in the JUICE mission: the Agenzia Spaziale Italiana (Italy); the Centre National d’Etudes Spatiales (France); the Deutsches Zentrum für Luft- und Raumfahrt e.V. (Germany); the Swedish National Space Board, and the United Kingdom Space Agency. Austria, Belgium, the Czech Republic, Greece, Poland, and Switzerland participate via the PRODEX programme.

I have to say I am very pleased to hear of the approval. The would leave just Uranus and Neptune with no spacecraft visits since Voyager. Who knows, Neptune Express anybody?

See the Geminid Meteor Shower

I was hoping to catch this shower. The expected rate is 80 per hour so this should be fun to watch.  Do check it out if you can.

Not likely to be any viewing for me thanks to clouds.   At least it isn’t supposed to snow; the 38 cm that has fallen since Wednesday is plenty.