The Young Astronomers
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NGC 2366 is a small, irregular dwarf galaxy 10 million light years away in the direction of the constellation Camelopardalis - the giraffe.
NGC 2366 Credit: NASAESA
[important]You can click on the image to view a larger version[/important]
The clearly visible blue region in the upper-right corner of the image is the star-forming nebula NGC 2363.
Broadly similar to the Milky Way’s satellite galaxies the Large and Small Magellanic cloud NGC 2366 may be small in comparison to many of the galaxies we are more accustomed to viewing in Hubble image though this doesn’t stop it from being a very active star factory indeed.
The smattering of active regions indicates that the galaxy is producing a great deal of the high mass blue stars (the blue smudges – and of course within NGC 2363).
The image was produced using Hubble’s infrared and green filters and so even though these regions appear blue they are actually a shade of red.
The image spans a distance of roughly 1/5 the diameter of the full moon though the galaxy itself is much too faint to be seen with the naked eye.
The view also captures a much more distant spiral galaxy which can be seen as the orange-brown structure in the upper middle portion of the image.
You can read more about the image here
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
Since the beginning of the Space Age, man has sent many manned and unmanned missions into space. Very powerful telescopes, built around the world, broaden our vision and understanding of the universe. Spacecraft, whether visiting other worlds or orbiting the Earth send us images and data collected from our outer atmosphere to the outer planets and beyond.
However, all this was only possible thanks to the incredibly rapid development of technology in recent years. Only then, could the essential resources for the construction of the current generation of spaceships be developed.
So, let us talk a little about some of the most important of space exploration’s tools and its greatest discoveries in this series, called Astronomy Tech.
In this first post, let’s get to know Cassini-Huygens a bit better. It is a joint mission between NASA, the European Space Agency (ESA) and the Italian Space Agency (ISA), which has uncovering the secrets of Saturn, including its rings and moons, as its primary objective.
An artist's impression of Cassini-Huygens Credit: NASA
On October 15th, 1997, the Cassini-Huygens spacecraft – composed of NASA’s Cassini orbiter and the ESA’s Huygens probe – was launched, beginning a long and complex seven-year journey, including gravitational slingshot manoeuvres around Venus, Earth and Jupiter. After arriving at its destination, the mother ship; Cassini, began its main objective exploring Saturn, whilst the Huygens probe was lunched and landed on Titan –Saturn’s largest moon and the second largest in the Solar System, after Jupiter’s moon Ganymede.
The spacecraft’s name was a tribute to the Italian Jean-Dominique Cassini (1625-1712) – discover of the Saturnine satellites Iapetus, Rhea, Tethys and Dione. In 1675 he discovered what is known today as the ‘Cassini Division’, the narrow gap separating Saturn’s A and B rings. Christiaan Huygens (1629-1695) was a Dutch scientist who first described Saturn’s rings and, in 1655 he discovered the moon Titan.
Cassini’s “senses”
The Cassini spacecraft has a set of 12 instruments on-board. Some of them work in similar ways to our own. However, the instruments on the Cassini spacecraft are much more advanced than our own.
Cassini can “see” in wavelengths of light that the human eye cannot. The instruments on the spacecraft can “feel” things about magnetic fields and tiny dust particles that no human hand could detect. This means that Cassini can, for example ‘see the temperature’ of the objects it observes.
The magnetic field and particle detectors take direct sensing measurements of the environment around the spacecraft. These instruments measure magnetic fields, mass, electrical charges and densities of atomic particles. They also measure the quantity and composition of dust particles, the saturation of plasma (electrically charged gases), and radio waves.
Exploring the Ringed Planet
The expected return to Saturn – which hadn’t been visited by any spacecraft since Voyager 2 left Saturn’s orbit in 1981, – happened in July 2004. Since then, Cassini has made great discoveries about the Saturnine System and taken some terrific pictures, like the one below.
An Eclipse of Saturn, with the Rings Visible Credit: Cassini/NASA
A few days after reaching Saturn, Cassini released the Huygens probe to land on Titan. On January 14, 2005, during its fall, six instruments analysed Titan’s atmosphere. According to the returned data, Titan has a nitrogen rich atmosphere. It also confirmed that Titan’s orange colour is due to the presence of hydrocarbons, formed when sunlight breaks down the abundant methane molecules within the atmosphere.
These results have given scientists a glimpse of what Earth might have been like before life evolved. They now believe Titan possesses many similarities to the Earth, including lakes, rivers, channels, dunes, rain, snow, clouds, mountains and possibly volcanoes.
Cassini’s mission
Isn’t over yet; every day, it sends us vast amounts of data back to astronomers allowing them to resolve and answer questions about Saturn and our own planet.
You can see more about Cassini on its official website. If you want to hear the news first hand, you can follow Cassini on Twitter.
240 miles above your head a 420 tonne satellite orbits the Earth at 17000mph. It has been there, albeit in various states of construction, for 14 years, and for the last 11 of those it has been continuously occupied.
The fantastic photo taken by Italian ESA astronaut Paolo Nespoli from a Soyuz capsule that is currently my desktop background. Source: ESA/NASA
The International Space Station is a feat of engineering like no other. Not only does it demonstrate our technical ability to construct, launch, and maintain a permanent presence in space, but also our ability to coordinate the work of five different space agencies and their operations all over the planet.
But the journey from its conception has not been an easy one, the ISS was born out of three separate national programmes: NASA’s Freedom station, proposed in the early ‘80s as a response to the Soviet space stations Mir and Salyut, the Russian (formerly Soviet) Mir-2 project designed as a replacement for the aging Mir station, and the European Columbus space station project.
Budgetary constraints brought on by post-Cold War political changes made it increasingly clear that no single national programme was going to create a fully functioning scientific outpost. Instead the suggestion to combine the three programmes into a single international one was put forward and agreed in 1993 by US Vice-President Al Gore and Russian Prime Minister Viktor Chernomyrdin.
The first component, the Russian Zarya cargo block originally intended for the Mir-2 station was launched in 1998, and since then the station has expanded, first with the addition of connecting and services modules such as NASA’s Unity and RKA’s Zvezda, and later with more specialist modules such as ESA’s Columbus laboratory and the Cupola observation module, the largest window in space. In total the ISS consists of fifteen pressurised modules, with one more, Russian research laboratory Nauka still to be added. They comprise laboratories, docks and airlocks, and living areas, and their combined volume is just less than 1,000 cubic metres.
That all of these modules fitted together perfectly is a success story in itself. Many had not been built when the first pieces were launched, and for most their mating in orbit was the first time they were put together. Though there have been a few minor problems, they have always been resolved quickly, and at no point has the station ever had to be evacuated.
The station’s unique conditions have allowed a large variety of experiments to be performed, many of which would be impossible on Earth. Research is being done into how structures such as crystals and organic cells form and develop outside the influence of the Earth’s gravity. NASA is also taking the opportunity to do closer studies on the effects of prolonged exposure to microgravity on astronauts and the possible implications on future manned missions to the Moon, asteroids, or Mars.
Until the end of the shuttle program in August of last year, crew and supplies were transported by a variety of means including the space shuttles, and the Soyuz and Progress spacecraft. The 6-man Soyuz craft operated by Roscosmos, the Russian Federal Space Agency, is now the only method of sending new crews to the station.
Each contributory nation retains ownership of and responsibility for the components that it added. This responsibility extends to the disposal of the station when it reaches the end of its operational life, which the current time frame places somewhere in the 2020s, depending on whether and for how long its decommissioning is postponed after the initial 2020 date. Given the huge amount of money that has been invested in the station as well as the later than expected completion date, it is very likely that the ISS’s operational life will be extended some way beyond that deadline. By that point it is also expected that commercial space ventures will play a much larger role in the life and upkeep of the station, so they too may play some role in its end-of-life decisions.
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.
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