Category: Astronomy

Have you ever really seen the night sky — a sky without any pollution from artificial light sources? Over half of Earth’s population lives in urban areas, and have probably never seen a rich, dark sky full of millions thousands of stars. Not only does light pollution make it harder for amateur and professional astronomers to observe the night sky, but it affects other living things as well. Birds and other animals that are nocturnal can become disoriented from constant artificial light.

You can help track how light-polluted our skies have become by participating in the GLOBE at Night Program. All you need to do is go outside and look for the constellation Orion and compare your view with sky charts provided by GLOBE and report your findings. The programs runs from now until March 8.

The GLOBE website provides you with information and links on how to find your latitude and longitude and how to find Orion. You then match your nighttime sky to one of their magnitude charts and report your observation. Then you can compare your observation to thousands around the world. Last year about 8,500 people participated in this event. Phil and Emily have already posted on this, but Universe Today is now joining in to help GLOBE have their night sky biggest event yet.

Also available from the GLOBE site are downloadable family activity packets and information for teachers, offered in several different languages. Take this opportunity share the wonders of the night sky with young children while helping to track light pollution. It will only take a few minutes.

NASA’s Swift satellite is pretty jittery as space telescopes go. It’s designed to wait until it detects a gamma ray burst, and then swing around quickly to start observing. But it’s actually equipped with some sensitive instruments, including a wonderful telescope designed for observing in the ultraviolet. In between searching for gamma ray bursts, Swift found the time to build up the most detailed ultraviolet image of an entire galaxy ever taken.

The ultraviolet spectrum is outside the normal range of visual light that we can see with our eyes. But it can sure affect you. Spend to much time out in the sunlight, and the ultraviolet radiation will give you a sunburn.

Young, hot, newly forming stars also give off a tremendous amount of ultraviolet radiation. Look at a galaxy in the ultraviolet, and you see the regions of star formation.

And that’s just what Swift did. The space telescope zeroed in on M33 – the Triangulum Galaxy. The galaxy is about half the size of the Milky Way, and located about 2.9 million light-years from Earth.

Even though it’s relatively small, M33 is awash in star formation.

“The ultraviolet colors of star clusters tell us their ages and compositions,” says Swift team member Stephen Holland of NASA Goddard. “With Swift’s high spatial resolution, we can zero in on the clusters themselves and separate out nearby stars and gas clouds. This will enable us to trace the star-forming history of the entire galaxy.â€?

This image is actually a mosaic of 13 individual images, captured between December 23, 2007 and January 4, 2008. Astronomers at NASA’s Goddard Space Flight Center then stitched the individual pieces together into a single image. It’s the most detailed ultraviolet image ever taken of an entire galaxy.

Original Source: NASA News Release

When researchers examine meteorites, they often find them sprinkled with teeny tiny diamonds – 25,000 times smaller than a grain of sand. In fact, these nanodiamonds make up 3% of the carbon found in meteorites. Astronomers think diamonds might actually be common out there in the Universe, and they’ve developed a new technique to find them.

The first hint of space diamonds came in the 1980s, when scientists studying meteorites discovered they were sprinkled with nanometer-sized diamonds. This has to be an indication of the environment of the stellar environment where the meteorites formed. There could be 10,000 trillion particles in a single gram of dust and gas.

Researchers at NASA’s Ames Research Center developed a computer simulation that simulated the conditions of the interstellar medium that would be rich in nanodiamonds. According to their simulation, clouds with these particles should be visible to NASA’s Spitzer Space Telescope.

The diamonds haven’t been seen in space because astronomers haven’t been looking in the right places. Since it takes a lot of high-energy ultraviolet light to make the diamonds shine, the researchers think Spitzer should be examining the environments around very hot, young stars, which produce large amounts of ultraviolet radiation.

Here on Earth, diamonds are formed by the intense heat and pressure of the Earth’s interior working over long periods. So how can they form in space? Instead of the heat and pressure we have on Earth, their environment is the exact opposite: diffuse clouds of cold molecular gas.

Astronomers aren’t sure, but now that they’ve got a technique to spot them with Spitzer, they’ll be studying gas clouds to understand the common conditions.

Original Source: NASA/Spitzer News Release

If you have an open horizon to the east on Tuesday, February 26, you’ll have the opportunity to spot Mercury and Venus together. Both inner planets will team up in their closest approach and appear to be about a degree apart in the pre-dawn sky. For those with a telescope, this will be an excellent time to catch both planets in different phases at the same time in the eyepiece!

For many of us, the chances to spot the swift inner planet – Mercury – are few and far between. While Mercury traditionally gets about as bright as the stars in the Big Dipper, it’s proximity to the Sun makes it hard to see either right after sunset or just before the dawn. Low clouds on the horizon, sky light, obstructing trees or buildings… many things combine to make Mercury notoriously difficult to observe. However, when a bright star – or in this case, a planet – is nearby, the task becomes a whole lot easier!

On the universal date of February 26, Mercury will appear low on the east/southeast horizon, precisely one hour before the Sun. Following it exactly two minutes later is brilliant Venus. Because of low position, chances are you’ll need binoculars to spot Mercury, but once your eyes have become accustomed, you may wish to try it unaided. The real treat will be to try and observe the pair telescopically. While it might seem dangerous since you’ll probably have to wait until the Sun is beginning to rise to catch them, don’t be afraid… It is perfectly safe to view them both during dawn.

Just like the phases of the Moon, both Mercury and Venus go through phases due to the relative position from which we view them. Take a look at the solar system as seen from above and you can easily understand why you see them as you do! Mercury will appear like the first quarter Moon, while Venus will be very gibbous. If you have filters, using them will help diminish the glare and make seeing the phases easier. If you do not. you can either wear a pair of sunglasses while at the eyepiece or wait until the skies begin to brighten. If the skies are cloudy, don’t worry. The pair will be visible for several mornings yet, but will begin to separate. Your observing job is to report which direction! Does Venus drop below Mercury or rise above?

Have fun!

Here are some fun facts about Mercury.

Are you ready for more meteor showers? Thanks to the after midnight rise of the Moon, many of us might have the clear skies to enjoy the Delta Leonid and Gamma Normid Meteor showers which peak around this date. While the activity isn’t dramatic for either one, these two rare meteor showers are a great time for observers to catch a shooting star!

For SkyWatchers who live in a dark area, be on the lookout for what is probably an ancient stream belonging to the Virginids. According to the International Meteor Organization (IMO) the “Northern hemisphere sites have a distinct advantage for covering this stream, especially this year as the waning gibbous Moon will rise around or after midnight at the peak for sites north of 35° N latitude. Southern hemisphere watchers should not ignore the stream, as they are better-placed to note many of the other Virginid radiants, but with moonrise as early as 22h 30m at 35° S latitude on February 25, conditions are not ideal.”

To take advantage of this opportunity, keep an eye on the constellation of Leo where meteors will seem to originate around mid-way in the Lion’s back. This is good news since the constellation itself will be visible nearly all night! The fall rates are slow – one about every 30 minutes – but with nearby Saturn to liven up the show, it’s a great time to catch a Delta Leonid telescopically. For the most part, the meteors you spot will be faint and blue. Using binoculars in this circumstance is definitely helpful as you’ll be able to see the trail far longer.

For the Southern Hemisphere, keep an eye out for the Gamma Normids, too! While they are similar to sporadic meteors, they are known to sometimes make a sharp jump in fall rate on either side of their peak time. IMO suggests: “Post-midnight watching yields best results, when the radiant is rising to a reasonable elevation from southern hemisphere sites. First quarter Moon on March 13 is thus excellent news, as it will set before midnight.” Again, the hourly rate is slow, but look for one about every 20 minutes. (Sorry, Northern Hemisphere… We can’t see Norma.) Shower members are swift with the brightest meteors often having a yellow color.

Neither the Delta Leonids, nor the Gamma Normids will be a spectacular show… But don’t despair if you don’t have clear skies tonight. Both meteor showers will be active until mid-March. The fun part is spotting one and understanding where it originated! While no definitive information can be found on the Gamma Normids, the Delta Leonids are thought to possibly be related to the minor planet 1987 SY – also known as asteroid 4450 Pan. The 1.6 km wide Apollo asteroid was discovered on September 25, 1987, by Caroline Shoemaker at the Palomar observatory and just made a flyby of the Earth on February 19, 2008, at a distance of 15.9 lunar distances (0.0408 AU). Perhaps we’ll be lucky and it will have left a bit more visible debris for us to enjoy!