As you probably know, I’m extremely active on Google+, and I think you’ll really enjoy it too. But I think people don’t realize how much the service really has to offer. People set up a Google+ account, don’t see any of their friends there, and then abandon it. The trick is that you need to circle really interesting people. Suddenly, your stream will fill with amazing content and compelling conversations – you’ll be hooked… like me.
Don’t worry that your friends aren’t on Google+. We’re there, and we’re more interesting.
And just to sweeten the deal, remember that we record every episode Astronomy Cast as a live Google+ Hangout. And now I’ve got access to Google+ Hangouts on Air, so we’ll be doing more live space and astronomy discussions, like the one we did yesterday with Phil Plait, Alan Boyle, Nancy Atkinson, and Emily Lakdawalla.
So let me help make this really easy for you with 3 simple steps:
Import my space circle, filled with 100+ bloggers, space agencies, and even an astronaut
At this point you should have 300+ amazing people to follow with very interesting conversations, you’ll be notified when we’re recording new Hangouts, and you can chat with me, Phil and most of the Universe Today team.
Here’s a great video that explains more about how to do this.
P.S. I know what you’re thinking, but I’m not getting compensated by Google+. 🙂
When Comet Lovejoy was approaching the Sun, many astronomers thought that it wouldn’t survive the journey when it reached the closest point of its orbit. And so everyone was surprised when it appeared on the far side of the Sun, battered, but still intact. Again, many astronomers predicted that it would now fade away as it traveled away from the Sun.
Well, guess what, Comet Lovejoy is now visible with the unaided eye… if you live in Australia, and you’re willing to get up at the crack of dawn.
Here’s a cool timelapse video of Comet Lovejoy rising in the morning captured by Colin Legg. You can see both the comet’s dust tail as well as its secondary plasma tail. Want to see more of Colin’s videos, check out his Vimeo page.
[/caption]
A big thanks to Mike Salway at IceinSpace for bringing this picture to our attention. And to Rod Brock on Google+ for opening my eyes to Comet’s Lovejoy’s potential as a bright comet.
[/caption]
Depending on how the calendar falls, the December solstice occurs annually on a day between December 20 and 23. This year, the December solstice will occur at 05:30 UTC (12:30 a.m. EST) on December 22, 2011. While the southern hemisphere is experiencing the long days of summer, the northern hemisphere will have the “winter solstice” – often called the shortest day of the year.
Conversely, six months ago the northern hemisphere experienced the longest day with the summer solstice, with the southern hemisphere having their winter solstice. This is part of a never ending cycle and is at the heart of our seasons.
So, why do we call it the shortest day of the year for the winter solstice and longest day for the solstice in the summer? Do we lose some time off the clock in winter, and in summer do we miraculously gain time on the clock in a bizarre cycle that is imposed by old men in charge of calendars and times around the world? (I used to think this as a small boy…)
The fact is we don’t lose or gain any time; what we actually gain or lose is hours of sunlight. During the winter solstice we receive the least amount of sunlight of the year on that day.
To understand the winter and summer solstices we need to recognize a fundamental fact about the Earth. Earth’s axis of rotation is tilted approximately 23.5° from a vertical axis. This means that as the tilted Earth orbits the Sun during the year, the different hemispheres receive varying amounts of sunlight, as this tilt causes sunlight to strike the surface of Earth at different angles at different times of year.
In the summer, we see the Sun for longer periods of time and it appears high in the sky; the Sun’s rays are more direct and the heat energy is more abundant. In the winter, when the Sun is low in the sky and appears for less amount of time; there is less energy and the Sun therefore heats less efficiently.
If you live near the equator, you won’t notice much difference in the amount of sunlight you receive throughout the year. The biggest noticeable difference is at the poles, where each solstice brings an extreme in the hours of sunlight you receive; in summer the Sun never properly sets for weeks, and in winter it never rises, creating some of the most inhospitable environments on Earth.
I always find the solstices to be magical times of year and look forward to either the longest or shortest days as they are the bringers of seasons, darkness and light.
A Soyuz rocket provided a little heat to frosty Kazakhstan, sending three new international crew members to the International Space Station. NASA Flight Engineer Don Pettit, Russian Soyuz Commander Oleg Kononenko and European Space Agency Flight Engineer Andre Kuipers of the Netherlands launched aboard their Soyuz TMA-03M craft at 13:16 UTC on Dec. 21 (8:16 a.m. EST, 7:16 p.m. local time), from the Baikonur Cosmodrome in Kazakhstan.
Pettit, Kononenko and Kuipers are scheduled to dock to the Rassvet module of the station at about 13:22 UTC ( 8:22 a.m.) Friday, Dec. 23. They will receive a holiday welcome from station the crew already aboard, Commander Dan Burbank and Flight Engineers Anton Shkaplerov and Anatoly Ivanishin. Continue reading “Soyuz Launches for Holiday Hookup with the International Space Station”
A pulsar within a supernova remnant in the Small Magellanic Cloud. X-rays are blue; optical data is red and green. (NASA/CXC/Univ.Potsdam/L.Oskinova et al.)
[/caption]
For the first time astronomers have located a pulsar – the super-dense, spinning remains of a star – nestled within the remnants of a supernova in the Small Magellanic Cloud. The image above, a composite of x-ray  and optical light data acquired by NASA’s Chandra Observatory and ESA’s XMM-Newton, shows the pulsar shining brightly on the right surrounded by the ejected outer layers of its former stellar life.
The optically-bright area on the left is a large star-forming region of dust and gas nearby SXP 1062.
A pulsar is a neutron star that emits high-energy beams of radiation from its magnetic poles. These poles are not always aligned with its axis of rotation, and so the beams swing through space as the neutron star spins. If the Earth happens to be in direct line with the beams at some point along their path, we see them as rapidly flashing radiation sources… sort of like a cosmic lighthouse on overdrive.
What’s unusual about this pulsar – called SXP 1062 – is its slow rate of rotation. Its beams spin around at a rate of about once every 18 minutes, which is downright poky for a pulsar, most of which spin several times a second.
X-ray image of SXP 1062
This makes SXP 1062 one of the slowest known pulsars discovered within the Small Magellanic Cloud, a dwarf galaxy cruising alongside our own Milky Way about 200,000 light-years distant.
The supernova that presumably created the pulsar and its surrounding remnant wrapping is estimated to have taken place between 10,000 and 40,000 years ago – relatively recently, by cosmic standards. To see a young pulsar spinning so slowly is extra unusual since younger pulsars have typically been observed to have rapid rotation rates. Understanding the cause of its leisurely pace will be the next goal for SXP 1062 researchers.
The Soyuz TMA-03M spacecraft is lifted on to the launch pad at the Baikonur Cosmodrome in Kazakhstan, Monday, Dec. 19, 2011. The rocket is being prepared for launch on December 21 to carry the crew of Expedition 30 to the International Space Station. Photo Credit: (NASA/Carla Cioffi)
[/caption]
Brrrr! It was frigid in Kazakhstan yesterday as the next Soyuz to the ISS rolled to the launchpad at the Baikonur Cosmodrome. Thermometers read a frosty 24 degrees below zero C, prompting astronaut Don Pettit to comment, “It is so cold that even microphones have a fur hat.” Pettit, Russian cosmonaut Oleg Kononenko and European Space Agency astronaut Andre Kuipers will launch aboard their Soyuz TMA-03M spacecraft at 13:16 UTC (8:16 a.m. EST) Wednesday, to bring the crew compliment on the ISS back to six.
You can watch the launch on NASA Television (coverage of the launch begins at 12: 30 UTC (7:30 a.m. EST) or on ESA’s website. ESA TV Live coverage starts for a lift-off (at 14:16) with inserts from Baikonur and TSUP Moscow Mission Control Centre and inside Soyuz capsule.
The trio will dock to the Rassvet module of the station on Friday. They will join their Expedition 30 colleagues Commander Dan Burbank from NASA and Russian Flight Engineers Anton Shkaplerov and Anatoly Ivanishin, who have been aboard the ISS since mid-November.
I apologize at low resolution and other issues. This is a work in progress and we’ll have things more organized in the future.
If you’d like to find out about and watch future Google+ Hangouts, head to Google+ and circle me. Then you’ll be notified with the Hangout is about to start.
The BRAVA fields are shown in this image montage. For reference, the center of the Milky Way is at coordinates L= 0, B=0. The regions observed are marked with colored circles. This montage includes the southern Milky Way all the way to the horizon, as seen from CTIO. The telescope in silhouette is the CTIO Blanco 4-m. (Just peaking over the horizon on the left is the Large Magellanic Cloud, the nearest external galaxy to our own.) Image Credit: D. Talent, K. Don, P. Marenfeld & NOAO/AURA/NSF and the BRAVA Project
[/caption]You may have heard about the restaurant at the end of the Universe, but have you heard of the bar in the middle of the Milky Way?
Nearly 80 years ago, astronomers determined that our home, the Milky Way Galaxy, is a large spiral galaxy. Despite being stuck inside and not being able to see what the entire the structure looks like — as we can with the Pinwheel Galaxy, or our nearest neighbor, the Andromeda Galaxy — researchers have suspected our galaxy is actually a “barred” spiral galaxy. Barred spiral galaxies feature an elongated stellar structure , or bar, in the middle which in our case is hidden by dust and gas. There are many galaxies in the Universe that are barred spirals, and yet, there are numerous galaxies which do not feature a central bar.
How do these central bars form, and why are they only present in some, but not all spiral galaxies?
A research team led by Dr. R. Michael Rich (UCLA), dubbed BRAVA (Bulge Radial Velocity Assay), measured the velocity of many old, red stars near the center of our galaxy. By studying the spectra (combined light) of the M class giant stars, the team was able to calculate the velocity of each star along our line of sight. During a four-year time span, the spectra for nearly 10,000 stars was acquired with the CTIO Blanco 4-meter telescope located in Chile’s Atacama desert.
Analyzing the velocities of stars in their study, the team was able to confirm that the Milky Way’s central bulge does contain a massive bar, with one end nearly pointed right at our solar system. One other discovery made by the team is that while our galaxy rotates like a wheel, the BRAVA study found that the rotation of the central bar is more like that of a roll of paper towels in a dispenser. The team’s discoveries provide vital clues to help explain the formation of the Milky Way’s central region. BRAVA data. Image Credit: D. Talent, K. Don, P. Marenfeld & NOAO/AURA/NSF and the BRAVA Project
The spectra data set was compared to a computer simulation created by Dr. Juntai Shen (Shanghai Observatory) showing how the bar formed from a pre-existing disk of stars. The team’s data fits the model quite well, suggesting that before the central bar existed, there was a massive disk of stars. The conclusion reached by the team is in stark contrast to the commonly accepted model of formation of our galaxy’s central region – a model that predicts the Milky Way’s central region formed from an early chaotic merger of gas clouds. The “take-away” point from the team’s conclusions is that gas did play some role in the formation of our galaxy’s central region, which organized into a massive rotating disk, and then turned into a bar due to the gravitational interactions of the stars.
One other benefit to the team’s research is that stellar spectra data will allow the team to analyze the chemical composition of the stars. All stars are composed of mostly hydrogen and helium, but the tiny amounts of other elements (astronomers refer to anything past helium as “metals”) provides insight into the conditions present during a star’s formation.
The BRAVA team found that stars closest to the plane of the Milky Way Galaxy have fewer “metals” than stars further from its galactic plane. The team’s conclusion does confirm standard views of stellar formation, yet the BRAVA data covers a significant area of the galactic bulge that can be chemically analyzed. If researchers map the metal content of stars throughout the Milky Way, a clear picture of stellar formation and evolution emerges, similar to how mapping CO2 concentrations in the Antarctic ice shelf can reveal the past weather patterns here on Earth.
Artist concept of the Membrane Optical Imager for Real-Time Exploitation (MOIRE). Credit: DARPA
[/caption]
“It sees you when you’re sleeping and knows when you’re awake” could be the theme song for a new spy satellite being developed by DARPA. The Defense Advanced Research Projects Agency’s latest proof-of-concept project is called the Membrane Optical Imager for Real-Time Exploitation (MOIRE), and would provide real-time images and video of any place on Earth at any time — a capability that, so far, only exists in the realm of movies and science fiction. The details of this huge eye-in-the-sky look like something right out of science fiction, as well, and it would be interesting to determine if it could have applications for astronomy as well.
MOIRE would be a geosynchronous orbital system that uses a huge but lightweight membrane optic. A 20-meter-wide membrane “eye” would be etched with a diffractive pattern, according to DARPA, which would focus light on a sensor. Reportedly it will cost $500 million USD for each space-based telescope, and it would be able to image an area greater than 100 x 100 km with a video update rate of at least one frame a second.
DARPA says the program aims to demonstrate the ability to manufacture large membranes and large structures to hold the optics flat, and also demonstrate the secondary optical elements needed to turn a diffraction-based optic into a wide bandwidth imaging device.
The MOIRE program began in March 2010 is now in the first phase of development, where DARPA is testing the concept’s viability. Phase 2 would entail system design, with Ball Aerospace doing the design and building to test a 16-foot (5 m) telescope, and an option for a Phase 3 which would include a demonstration of the system, launching a 32-foot (10 m) telescope for flight tests in orbit.
The 20 meter (66 ft) design is quite a bit larger than NASA’s next-generation James Webb Space Telescope that has an aperture of 21 feet (6.5 m).
Public Intelligence reports that such a telescope should be able to spot missile launcher vehicles moving at speeds of up to 60 mph on the ground, according to a DARPA contract. That would also require the image resolution to see objects less than 10 feet (3 m) long within a single image pixel.
Can we order one for looking for extrasolar planets?
Artist's Concept of Kepler-20f. Credit: NASA/Ames/JPL-Caltech
[/caption]
Want more information about the recent discovery of Earth-sized planets by NASA’s Kepler Mission? I’ve gathered together a team of scientists and astronomy journalists to talk about the announcement. We’ll explain the discovery in detail, give you some context, and then answer questions from the viewers.
We’re doing this as a Google+ Hangout on Air, which is in a beta state right now, so there could be all kinds of technical issues, but we’ve tested this out and it’s really cool.
Our current team will be me (Fraser Cain, Publisher of Universe Today), Nancy Atkinson – Senior Editor of Universe Today, Bad Astronomer Phil Plait, the Planetary Society’s Emily Lakdawalla and MSNBC Science Editor Alan Boyle. I suspect we’ll have a few more joining us too.
I’ll post a link to the Hangout once we’ve gone live, just after Noon, so check back then.
If you want to get notified, head over to Google+ and circle me, Nancy, Phil, Emily or Alan and you’ll see the broadcast in your stream once we get started.
The broadcast is over. I’ll post the video once I get my hands on it.
