Aurorae on Uranus

Hubble has for the first time spotted Aurorae on the distant ice giant Uranus. In the image below you can see the turquoise disk of the planet has a bright ‘blotch’.

Uranus' Aurorae Credit:NASA, ESA, and L. Lamy

An aurora is produced when a stream of charged particles from the solar wind (the material ejected from the Sun) collides with a planet’s magnetic field (more properly called its magnetosphere) and excites the particles within the atmosphere casing them to glow. This glow is what we observe as the aurora.

On Earth aurorae with a blue or red colour are due to excited nitrogen, whilst green or a redish brown hue is due to excited oxygen. The aurorae can dance across the sky in waves of coloured light and whilst some last for a few brief minutes others can remain active for hours depending on the conditions creating them – solar storms for example can create very powerful aurorae.

Aurorae have been observed on other planets as well, particularly Jupiter and Saturn; both of which have prominent auroral systems. Those present in Uranus’ atmosphere are considerably fainter and appear to last only for a few short minutes at a time.

These images represent the first observation of Uranus aurorae, with previous data collected directly during the Voyager 2 flyby in 1986.

These new observations should help to reveal more about Uranus’ magnetic field, which we currently know little about.

You can read more here

Social Science – Science140

Last week saw the launch of a new science project on twitter:

The project is hoping to collect as many science based definitions, explanations and facts all in the form of tweets which contain no more than 140 characters.

No small feat!

The project is looking for as many people to contribute as possible on all topics of science right through from Astrophysics to Zoology. Best of all anyone can take part regardless of age or experience.

What is the goal of this project you ask?

We aim to collect these definitions, explanations and biographies over the next three months in the hopes of collating them in to a book – the proceeds of which will go to charity. Details of the charity / charities will be released in the coming weeks.

Fun education from all, for all and helping out a good cause to boot, what could be better!

You can learn more about the project on the official website and on twitter by following @science140

Submitting a tweet for the project is easy, just include the hash tag – #science140

So what are you waiting for! Dust off your facts and get tweeting!

Image of the Week – Hubble’s Birthday Treat – 17/04/12

In celebration of the Hubble Space Telescope’s 22nd anniversary the ESA has released this truly stunning image of the star forming region 30 Doradus.

30 Doradus Credit: NASA, ESA, ESO, D. Lennon and E. Sabbi (ESA/STScI), J. Anderson, S. E. de Mink, R. van der Marel, T. Sohn, and N. Walborn (STScI), N. Bastian (Excellence Cluster, Munich), L. Bedin (INAF, Padua), E. Bressert (ESO), P. Crowther (Sheffield), A. de Koter (Amsterdam), C. Evans (UKATC/STFC, Edinburgh), A. Herrero (IAC, Tenerife), N. Langer (AifA, Bonn), I. Platais (JHU) and H. Sana (Amsterdam)

30 Doradus is better known as the Tarantula nebula and is located 170,000 light years away within the Milky Way’s largest satellite galaxy the Large Magellanic Cloud (LMC).

The image shows a region of space approximately 650 light years across with several million stars present within. Combined, the sum total of the stars’ masses shown in this image would be well over a million times the mass of our own Sun.

The stars are grouped into smaller clusters ranging in age from about 2 million – 25 million years old, whilst this may sound ancient in human terms as far as the universe is concerned even the oldest star in the region is a newcommer.

The brightest cluster is NGC 2070 being one of the youngest (between 2 and 3 million years old) and most actively starforming regions with the larger structure Astronomers find it an attractive region to study. Recently in fact, it was revealed that at the heart of the cluster (which contains upwards of half a million stars) there is a dense clump of stars designated RMC 136 where the largest stars yet discovered reside. Indeed several of these monsters are more than 100 times the mass of our own sun, truly cosmic giants.

The fierce output of the regions hot stars sculpts the regions gas and just into the fantastic arcs and bubbles we can see in the image. The fierce radiation bombardment of radiation is also exciting the gas and dust molecules of the nebula making them glow in their own right and classing the region as an emission nebula.

The image is composed of data from both Hubble and the ESO’s MPG/ESO 2.2-metre telescope and represents the one of the largest such mosaics in existence today. The data was captured by both telescopes during an observing run in October 2011.

You can read more here.

WISE Shows the Sky is Awash with Blazars

The latest release from NASA’s WISE mission has shown that just over 200 previously unidentified high energy objects are likely to be blazars.

Artist's Impression of an active Blazar Credit:NASA/JPL-Caltech

A blazar is a form of active galactic nucleus (AGN) – a galaxy where the central black hole is ‘feeding’ on large amounts of material resulting in the release of huge amounts of radiation including two tight very bright jets.

The angle at which the AGN is situated relative to the Earth determines which form of AGN we observe even though all are tied to the same processes.

In the case of a blazar we are looking directly down the AGN’s jets you could even say right down the barrel of the gun!

AGN at various angles; Credit: Aurore Simonnet, SSU NASA E/PO.

As the AGN must be lined up almost exactly with Earth for a blazar to be observed they are understandably rare compared to the other forms of AGN which have a much larger range of possible viewing angles. That being said the WISE data has the potential to reveal several thousand more.

A team using the WISE data looked at 300 objects that had previously been detected as high energy gamma-ray sources by the Fermi Space Telescope, though up to now had remained unidentified.

Using WISE the team was able to observe these gamma ray hotspots in infra-red wavelengths and showed that just over half are most likely to be blazars. WISE had also observed 50 new blazars outside those Fermi oddities along with taking observations of more than 1000 previously identified blazar candidates.

One of the project leads, Francesco Massaro has explained that there may be several thousand more as of yet unknown blazars hidden within the WISE data that could be revealed using the techniques developed for this first sample.

An image of one of the new WISE identified blazars Credit:NASA/JPL-Caltech/Kavli

You can read more here

 

Origins of the Moon Challenged

The commonly accepted theory among scientists concerning Moon formation could be altered by a new study of lunar isotopes. (Variations of elements containing differing amounts of neutrons).

Luna Credit: NASA

Nearly half of the Moon was postulated to be from Theia, a planetary body, thought to have collided with Earth four point five billion years ago. The recent study by Junjun Zhang, an isotope geo-chemist at the Chicago Center for Cosmo-chemistry and his team challenged this premise. Initially, an analysis of twenty-four rocks from the lunar surface revealed a paucity of indications concerning similarities between the Moon and Earth. However, the group failed to consider the effect of cosmic rays, streams of charged particles racing through space. After amending their research on the Moon’s isotopes of titanium, they found its ratio to be in the ballpark of our planet’s chemistry.

The unlikelihood of Theia’s chemistry being nearly identical to the Earth prompted scientists to reconsider their model. They theorized, perhaps the planetary body collided and caused more joining of debris than previously suggested. This could infer, the majority of Theia’s constitution is hidden deep within the Moon, while Earth’s composition lays conspicuously on the surface.

Suggestions of a collision between a dual moon systems arose as well, inferring that one of our past satellites had a chemistry similar to the Earth. Scientists cannot know for sure, whether their ideas are correct or not, they are still theories. However, the research team plans on conducting more experiments on the isotopes of different elements found on the Moon.

You can read more about these findings at http://news.yahoo.com/moon-formation-theory-challenged-study-160608598.html

Image of the Week – Martian Dust Devil Goes for a Spin – 09/04/12

NASA’s Mars Reconnaissance Orbiter has produced a truly stunning image of a Martian dust devil using its High Resolution Imaging Science Experiment (HiRISE) instrument.

The Martian Dust Devil Credit: NASA/JPL-Caltech/UA

The Devil is about 12 miles high (though only 70 meters across) and was produced as the Sun warmed the ground in such a way that a vortex was created. This sort of weather feature is most common when the sun’s heating effect is felt most strongly and fittingly this particular event occurred just two weeks before the northern hemisphere’s summer solstice.

NASA scientists have put together this video showing the dust devil in action

You can read more about this weather phenomenon here

Potential Research at the Poles

Note from the Young Astronomers Admin Team:

This is the first by our new editor YusefK and we would all like to welcome him to the team!

When you picture the world’s best site for astronomy, places like the Gemini Observatory in Chile or the W.M. Keck in Hawaii probably come to mind. Well think again, because the new epicenter of observing could be the coldest place on earth, Antarctica. After performing a careful analysis of the continent, scientists from America and Australia have pinpointed a prime location for ground based research. Several countries have already laid claim to the icy real estate, such as China, France, Russia and South Africa. The success of these countries’ scientific bases led to the development of more stations. We could owe our future understanding of the universe to those who work and live in this region.

Antarctica Credit: NASA, Davepape

Radio astronomers have already conducted research in the polar area. It was Martin Pomerantz who postulated that Antarctica was the best place for ground based astronomy. He was correct, but only under certain wavelengths. Until now, those who wanted to see the universe were out of luck. Nevertheless, the new site found by American and Australian scientists is expected to yield images three times sharper than today’s best observatories. Those of us who spend clear nights under the stars understand the importance of certain atmospheric factors. Things like water vapor in the air, temperature changes and darkness greatly affect our observing.

The location of this new site is a frozen plateau called Ridge A. Ridge A’s atmosphere is steady enough for average instruments to perform better than today’s common observatories. Imagine the potential of an eight inch Cassegrain in perfect weather conditions and the images would be stunning, when the larger facilities are established. The night sky above the summit is perfect for astronomical observing because it is calmer, dryer and darker than any ever known. Those who study and live in Antarctica will benefit from this treasure trove of unexplored skies. However, they will have to contend with several inhospitable factors foreign to the common scientist.

Living in Antarctica seems to be a challenge taken by the very eccentric or very passionate. Generally, scientists take a plane to the Falkland Islands and then a ship to Antarctica. There, they work with several professionals in the coldest and driest place on earth. Nevertheless, I have read the quarters are comfortable and the canned food isn’t half bad, either. Scientists work with a diverse group of people for months at a time and under strange and adverse conditions. So, for all budding astronomers and researchers, consider the South Pole for future endeavors in understanding the universe.

Sources:

http://www.antarctica.ac.uk/employment/locations/antarctica/living_in_antarctica.php

http://www.nsf.gov/pubs/1997/antpanel/4past.htm

http://www.physorg.com/news170932769.html

http://www.universetoday.com/38749/astronomers-find-worlds-best-observing-site/

Stellar Newborns Kick Up a Fuss

The Orion nebula is the closest region of large scale star formation to Earth sitting just 1340 light years from where you are reading this post.

The nebula is in the process of birthing the next generation of stars, with many still cocooned within the clouds from which they are forming, from peering eyes. Well that’s in the visible spectrum at least. Using infra red observations we can looks through the obsuring dust as if it isn’t there at all.

This is exactly what astronomers using the Sptizer and Hershel Space telescopes have done to produce this gorgeous image:

The Orion Nebula in I-R Credit: NASA/ESA/JPL-Caltech/IRAM

The rainbow effect is due to the combination of different sets of observations through different filters. by combining the individual images the compound image can reveal the nebula in stunning detail with each colour displaying a different wavelength of I-R radiation. Using two telescopes also has advantages, as Sptizer is designed to observe at shorter wavelengths than Hershel and so by combining the two sets of data astronomers can get a more complete view of what is going on.

In this case the data revealed something very unusual indeed. Several of the young protostars have been flickering wildly, with their brightness fluctuating by as much as 20% in just a few weeks. Based on the cool temperatures of the material involved, the fluctuations had to occur far from the hot regions near the growing star, but such material should be far enough away from the star to spend years or even centuries in a slow decaying orbit before accreating onto the star’s surface.

Currently the explanation for how such a process could be so drastically accelerated is still up for debate though there are several suggestions. The other material may not be evenly distributed around the star, with some regions being more densely occupied than others. That may allow some of the denser clumps or filaments to collide with an inner, warmer shell of material causing the flare ups. It could also be caused by material piling up at the edge of the inner disk and so casting a shadow on the outer disk.

You can read more about this image here and here

Image of the Week – Hubble Spies A Glittering Jewel

The NASAESA Hubble Space Telescope has obtained the highest quality image of the globular cluster Messier 9 (M9) ever produced.

Messier 9 as seen by Hubble Credit: NASAESA

This glorious sphere of stars is far too faint to be detected by the human eye, yet Hubble can resolve it as upwards of a 1/4 of a million individual glistening stars.

M9 sits towards the centre of our own galaxy, and yet whilst relaivly close by in the grand scale of the universe it is still 25,000 light years from Earth.

The stars within M9 are twice the age of our own sun and are metal poor as a result – as they formed at a time when the cosmos was still largely deprived of the heavier elements like iron, oxygen and nickel.

The cluster was first discovered in 1764 by the French astronomer Charles Messier and was included as object 9 on his list of astronomical objects (hence its name!).

The image above covers and area of sky roughly equal to a pin head held at arms reach,a true testiment to the power of Hubble.

You can read more here

ATV 3 – Edoardo Amaldi – Successfully Docks with the ISS

Yesterday the third in the European Space Agency’s (ESA) line of Automated Transfer Vehicles (ATV) – The Edoardo Amaldi docked successfully with the International Space Station (ISS).

The craft brings 7 tons of food, water and other cargo to the station. It will remain docked for six months before being loaded with the station’s refuse prior to being de orbited and destroyed by atmospheric re-entry heat.

The next two ATVs planned are ATV-4 Albert Einstein, which is to be launched in 2013 followed by ATV-5 Georges Lemaître in 2014.

Schematic of an ATV Credit: ESA