The day has finally come. We now have direct, infrared and optical observations of planets orbiting other stars. Yesterday, reports from two independent sources surfaced, one from the Gemini and Keck II observatories and the second from the Hubble Space Telescope. Brace yourself for an awe-inspiring display of planets orbiting two stars…
The Gemini/Keck observations were carried out using adaptive optics technology to correct in real-time for atmospheric turbulence. The stunning images of a multiple planetary star system were then constructed from infrared emissions (the image, top, was constructed by Keck II as a follow-up to to the Gemini observations). The system in question is centred around a star called HR 8799, approximately 130 light years from Earth and in the constellation of Pegasus. The entire press release can be found at the Gemini observatory site, where they give the discovery a full run-down.
On the same day, the Hubble Space Telescope team also released images of one extrasolar planet, only this time in optical wavelengths. Although the exoplanet in Hubble’s images is less obvious than the infrared Gemini/Keck II images, incredible detail has been attained, showing a ring of dust around the star Fomalhaut (located in the constellation of Piscis Austrinus). Fomalhaut is 25 light years away and the star’s daughter planet (Fomalhaut b) is only a little under 3 Jupiter masses.
But that doesn’t mean it’s close. The Kuiper belt exists in a region of space 30–55 AU from the Sun; this is where Pluto lives (as Pluto itself is a “Kuiper belt object”, or KBO). As astronomical techniques become more advanced however, we are able to discover more KBOs in the zoo of icy-rocky bodies that live in this region.
At long last, we have visual evidence of the 2008 TC3 impact over the remote Sudanese skies. Admittedly, it’s not a video of the dazzling fireball ploughing though the upper atmosphere, before detonating with the energy of a small nuclear weapon, but it is a great picture of the smoky remnant after the explosion.
The meteorite train seen in the image above has been sheared and twisted by high altitude winds, leaving the snake-like pattern suspended in the air. The tenuous debris reflects the dawn sunlight, in a not-so-dissimilar way to the noctilucent cloud produced after a rocket launch (pictured left).
Armed with the most basic photography device and plenty of time, Justin Quinnell has captured some of the most unique and entrancing views of the Sun over my hometown of Bristol. When I first saw this image, the iconic Clifton Suspension Bridge instantly jumped out at me. It took me a while to figure out what was going on, but after getting engrossed in Justin’s website all about pinhole photography, I soon realised this was a six-month exposure, capturing the Sun’s motion from winter solstice (December 21st, 2007) to summer solstice (June 19th, 2008)… Continue reading “Pinhole Camera Solargraphy”
2001 QW322 is a highly split Kuiper Belt pair, orbiting eachother at a distance of 125,000 km
The Kuiper Belt is an eerie, mysterious and cold region of the Solar System. In it, there are billions of small pieces of rocks with lots of fancy names. As a general designation, all objects in the Kuiper belt are called “Kuiper-belt objects” (KBO’s for short). As the Kuiper belt is located in a region just beyond Neptune, they may also be known as trans-Neptunian objects (TNO’s). Inside the Kuiper belt, we have Pluto-like objects known as “Plutoids”, classical KBO’s called “Cubewanos” (the largest being the recently discovered Makemake) and a whole host of other objects such as icy objects soon to become the next generation of periodic comets.
We are only scraping the surface, finding only a small portion of KBOs. We know of a thousand, but astronomers believe there may be as many as 70,000 measuring over 100km in diameter, plus countless other smaller objects.
A stunning series of videos from seven all-sky cameras in the The University of Western’s Southern Ontario Meteor Network (SOMN) captured the same fireball generated by a meteor entering the atmosphere pre-dawn on the morning of September 15th. Whilst meteors aren’t uncommon (if you hang around outside for long enough you might see one or two “shooting stars” yourself), this fireball was very bright and had a surprisingly slow velocity. What’s more, astronomers think that the extraterrestrial object came from a typical Earth-crossing orbit, possibly indicating this was another small near-Earth asteroid. In fact, meteorite hunters believe that it may have slowed significantly when passing through the atmosphere, dropping fragments to the ground. A great catch by the Canadian team, let’s get searching! Continue reading “Rare Meteor Fireball Captured by Seven Canadian Cameras (Videos)”
Rocks are being thrown at us, but we haven’t noticed
On October 7th, a small asteroid called 2008 TC3 exploded in the skies above Sudan. On October 9th, a metre-wide asteroid named 2008 TS26 buzzed Earth’s atmosphere by only 7000 km. Then on the 21st (Tuesday) a slightly bigger piece of rock called 2008 US missed us by 25,000 km. It sounds like it’s getting dangerous out there, especially when considering the last recorded object (2004 FU162) to come screaming past the Earth (at 6500 km) happened in 2004.
There may not be any ground-based imagery of the 1.1-2.1 kT fireball after asteroid 2008 TC3 hit the Earth’s upper atmosphere above Sudan, but we now have the first satellite observation of the impact. 2008 TC3 (a.k.a. “Brian” as I lovingly named it in my previous post) hit at 02:43am (UTC) yesterday morning, three minutes before the predicted re-entry. This is a huge moment for asteroid hunters: 2008 TC3 is the first ever asteroid to be discovered and accurately forecast to hit our planet.
The above image was taken by the weather satellite Meteosat 8, as Jiri Borovicka of the Czech Academy of Sciences explains: “The explosion was visible in all 12 of the satellite’s spectral channels, covering wavelengths from 0.5 to 14 microns,” he said. “The satellite takes pictures every five minutes; the fireball appeared at 0245 UTC and had faded away by 0250 UTC.”
2008 TC3 wasn’t a particularly interesting asteroid. It wasn’t very big (only 1-5 metres wide) and it didn’t really stand out as being special (if it was special, we didn’t have any time to realise it anyway). If 2008 TC3 was in a crowd of other asteroids you wouldn’t have picked it out. In fact, it was that “normal” that it wasn’t named, it just kept its original asteroid designation number. 2008 TC3 was an ordinary piece of space rock in an extraordinary situation.
A newly discovered asteroid called 2008 TC3 will (with a 99.8-100% probability) hit the atmosphere over northern Sudan at 2:46 UTC (Oct 7th). The piece of rock will not threaten people or structures on the surface, it is likely to burn up during re-entry as a magnificent “air burst.” Estimates suggest that as 2008 TC3 burns up, it will detonate with an energy of a kiloton of TNT.
2008 TC3 is between 1-5 meters in diameter, so it’s not a threat by any means, but it should create a spectacular display. Usually the bright meteors we observe are generated by debris no bigger than a grain of sand, so this will be a huge astronomical event in comparison. The giant meteor will be visible from eastern Africa travelling very quickly from north-east to south-west and it is expected to create a very long trail as it will enter the atmosphere at a very shallow angle. Continue reading “Small Asteroid 2008 TC3 Will Hit Earth Tonight”