Hunt for Sunset Mercury this Weekend

Written by The Night Sky Guy on July 31, 2009 – 10:45 am -

click to enlarge

click to enlarge

Up for a skywatching challenge the next few evenings? Try to spot little Mercury hanging super low in the western horizon. The innermost planet will only be 9 degrees or so above the western horizon just after sunset. That is about equal to your fists width at arms length. Luckily faint star-like Mercury will be easier to find thanks to the nearby, much brighter star Regulus – lead member of the constellation Leo. Friday night the pair will be separated by only 3 degrees – equal to about 6 full Moon disks apart with Mercury to the right of Regulus. But by Sunday evening the pair has its closest encounter with faint Mercury sitting just above Regulus – only a half degree apart – equal to only one full Moon disk apart! A very cool sight – don’t miss it. If you have never seen this tiny planet, Regulus will act as a great guidepost in tracking down your target. Remember to be patient in finding Mercury – it is considered the most difficult of all the five classical naked-eye planets to see in the sky. Tip – find a viewing location that is clear of any obstruction of the western horizon and also binoculars will help a lot in spotting it in the dusk’s glare. As an added bonus to the far upper left of the pair, will be the much brighter planet Lord of the Rings, Saturn. Good luck with your planetary hunt!


Tags: ,
Posted in Planets, Solar System, Stargazing, stars | 473 Comments »

Radio Show: The Scoop on Scopes

Written by The Night Sky Guy on July 29, 2009 – 2:27 pm -

Coming up on my next CBC Radio One column today (Wednesday) we talk about how to buy and use that first telescope. Are you thinkng of getting a scope for yourself or maybe the kids? Or something lightweight for the country cottage or that trip to a remote, exotic locale? I’ll give you the scoop on scopes. Tune in to the drive-home show between 3 pm and 6 pm on your city’s local CBC Radio One station.

For more info check out these online resources on telescopes:

The Uncluttered Telescope Buyers Guide
Download SkyNews Mag’s Guide to Best Telescope Buys under $ 1000 (PDF) (2002)
Sky & Telescopes Guide to Choosing a Telescope
Astronomy’s Buyers Guide

Some leading telescope manufacturers:

Meade instruments
Celestron

Skywatcher
Orion


Tags:
Posted in Uncategorized | 292 Comments »

Monster Star Comes into Focus

Written by The Night Sky Guy on July 29, 2009 – 9:13 am -

Stars are so far away that most telescopes, even some of the largest, cannot resolve them into disks. They simply appear as a point of light. Now all that is changing, thanks to a new technique where the power of three giant telescopes can be combined as one.  Now astronomers have taken the sharpest view of a dying mammoth star ever made (see image on right).  Even with Earth’s turbulent, image-distorting atmosphere in the way, the resolution of the red giant Betelgeuse is as fine as 37 milliarcseconds, which is roughly the size of a tennis ball on the International Space Station (ISS), as seen from the ground.

For the first time they could show, how the gas is moving in different areas over the surface of a distant star. This latest news on the famous bright star, Betelgeuse, in the constellation Orion, comes on the heels of the discovery last month that the same star is skrinking in size. This new accomplishment was made possible by combining three 1.8 m telescopes as an interferometer, giving the astronomers the resolving power of a virtual, gigantic 48 m telescope. Using the ESO VLT Interferometer in Chile, they discovered that the gas in the dying star’s atmosphere is vigorously moving up and down, but the size of such “bubbles” is as large as the star itself. These colossal bubbles are a key for pushing material out of the star’s atmosphere into space, before the star explodes as a supernova.

Artists impression, showing how a vast amount of material is flung out from Betelgeuse into space.

Artist's impression, showing how a vast amount of material is flung out from Betelgeuse into space.

Betelgeuse in Orion

Betelgeuse in Orion

When one looks up the clear night sky in winter, it is easy to spot a bright, orange star on the shoulder of the constellation Orion (the Hunter) even in light-flooded big cities. That is Betelgeuse. It is a giant star, which is so huge as to almost reach the orbit of Jupiter, swallowing the inner planets Mercury, Venus, Earth, and Mars, when placed at the center of the solar system. It is also glaringly bright, emitting 100 000 times more light than the Sun. Betelgeuse is a so-called red supergiant and approaching the end of its short life of several million years. Red supergiants shed a large amount of material made of various molecules and dust, which are recycled for the next generation of stars and planets possibly like the Earth. As a matter of fact, Betelgeuse is losing material equivalent to the Earth’s mass every year.

The death of the mammoth star, which is expected in the next few thousand to hundred thousand years, will be accompanied by cosmic fireworks known as a supernova like the famous SN1987A. However, as Betelgeuse is much closer to the Earth than SN1987A, the supernova can be clearly seen with the unaided eye, even in daylight.

- Adapted from material taken from a news announcement by the Max-Planck-Institut for Radio Astronomy

click image to enlarge

click image to enlarge

Doorstep Astronomy: You can check out Betelgeuse and its host constellation Orion in the early morning sky. Look towards the eastern horizon about a half hour before local sunrise and you should be able to make out the belt of three stars and the distinct orange-hued Betelgeuse sitting to their upper left. If the glare from the dawn is giving you a hard time finding the red giant, then use the super-bright, star-like Venus (brightest star in the sky) and just scan over to its right side and you should see 429 light year distant Betelgeuse stand out.
 

 

 

 

Tags: ,
Posted in stars | 291 Comments »

Impact Risks for Earth

Written by The Night Sky Guy on July 28, 2009 – 3:47 pm -

With Jupiter just being smacked again by a potential comet or asteroid, the media are abuzz once more with the discussion of our own planet being in danger from a doomsday rock from space. What exactly are the risks?  Space.com ran an interesting story today where astronomer Donald Yeomans, manager of NASA’s Near-Earth Object program office at the Jet Propulsion Laboratory, was asked how well we were doing in tracking down wayward asteroids that may have Earth in their cross-hairs.  Turns out that its the highrise-sized boulders, not the giant, city-sized dino-killers that we need to possibly watch out for in the short-term, ie. in our lifetime.

“Researchers suspect about 156 large NEOs 1 kilometer in diameter or larger remain to be found, and when it comes to dangerous NEOs in general, “when we get down to 140 meters (460 feet) or larger diameter objects, we think we’ve discovered about 15 percent of them, and with 50 meters (164 feet) or larger diameter, we’ve discovered less than 5 percent of them,” Yeomans explained.

On average, an NEO roughly a half-mile wide or larger hits the Earth roughly every 500,000 years, “so we’re not expecting one anytime soon,” Yeomans explained.

“For 500 meters (1,640 feet), we’re talking a mean interval of about 100,000 years,” he added. “When you get down to 50 meters, the mean interval is about 700 years, and for 30 meters (98 feet), about 140 years or so, but by then you’re getting down to a size where you won’t expect any ground damage, as they burn up in the atmosphere at about 25 meters (82 feet) in diameter and smaller, probably for an impressive fireball event.”"

I am not sure that all of them would burn up in the atmosphere at those sizes however. There have recently been much talk in the science community that even air bursts of building sized rocks, if they are solid enough can produce extensive local damage. There is still way too much speculation going on without any definite answers as to what the real dangers are. Hopefully cosmic impact events like this past week and the resulting chatter will result in more vigorous research into this field. After all, our life may depend on it. 


Tags: , ,
Posted in Meteors, Solar System | 378 Comments »

Mini Meteor Shower Tuesday

Written by The Night Sky Guy on July 27, 2009 – 12:28 pm -

click image to enlarge

click image to enlarge

Skywatchers get a chance to have their appetites whetted for the upcoming Perseids, with a small meteor shower peaking late Tomorrow (Tuesday) night.  Known as the southern-Delta Aquarids, this relatively little known event occurs annually and produces about 20 shooting stars at its peak time – around 10 pm tomorrow to 1 am (Wednesday).  You may have already noticed above average number of shooting stars at night as we are leading up to the peak for this shower.  The meteors themselves are sand grain sized particles that are in a giant cloud in space. most probably debris left behind by a comet that shed its dust. Every year, Earth slams into this cosmic dust cloud producing the Aquarid shower.

Like all other showers the Aquarids are named after the constellation from which the meteors seem to originate from in the sky. In this case its the famous zodiac constellation Aquarius. A generally faint pattern of stars, Aquarius rises above the local eastern horizon about 11 pm and is easier to locate this summer thanks to the planet Jupiter, which is the brightest star-like object in that part of the sky . So it’s after that, when you should start to see an increase in shower activity.  From a dark location away from light polluted cities you could see one meteor every 5 minutes or so.


Tags: , ,
Posted in Constellations, Meteors | 262 Comments »

Galactic Hurricane’s Eye

Written by The Night Sky Guy on July 26, 2009 – 3:51 pm -

Click to enlarge

Click to enlarge

NASA’s Spitzer Space Telescope has imaged a wild creature of the dark — a coiled galaxy with an eye-like object at its center. The galaxy, called NGC 1097, is located 50 million light-years away. It is spiral-shaped like our Milky Way, with long, spindly arms of stars. The “eye” at the center of the galaxy is actually a monstrous black hole surrounded by a ring of stars. In this color-coded infrared view from Spitzer, the area around the invisible black hole is blue and the ring of stars, white.The black hole is huge, about 100 million times the mass of our sun, and is feeding off gas and dust along with the occasional unlucky star. Our Milky Way’s central black hole is tame by comparison, with a mass of a few million suns. The ring around the black hole is bursting with new star formation. An inflow of material toward the central bar of the galaxy is causing the ring to light up with new stars. In the Spitzer image, infrared light with shorter wavelengths is blue, while longer- wavelength light is red. The galaxy’s red spiral arms and the swirling spokes seen between the arms show dust heated by newborn stars. Older populations of stars scattered through the galaxy are blue. The fuzzy blue dot to the left, which appears to fit snuggly between the arms, is a companion galaxy.


Tags: , , ,
Posted in Satellites, stars | 467 Comments »

Hubble Eyes Jupiter’s Scar

Written by The Night Sky Guy on July 25, 2009 – 11:33 am -

Check out this amazing hi-rez photo taken by the revamped Hubble of the recent impact on the king of all planets. Even though the space scope is still undergoing testing, scientists decided that this impact was too big of a science event to miss out on so they decided to turn Hubble on Jupiter. What a sight!

Click image to enlarge

Click image to enlarge


Tags: ,
Posted in Planets, Solar System | 2 Comments »

New Light on Old Explosion

Written by The Night Sky Guy on July 23, 2009 – 12:55 pm -

Ten years ago, on July 23, 1999, NASA’s Chandra X-ray Observatory was launched aboard the space shuttle Columbia and deployed into orbit. Chandra has doubled its original five-year mission, ushering in an unprecedented decade of discovery for the high-energy universe.

 This image of the debris of an exploded star — known as supernova remnant 1E 0102.2-7219, or “E0102″ for short — features data from NASA’s Chandra X-ray Observatory. E0102 is located about 190,000 light years away in the Small Magellanic Cloud, one of the nearest galaxies to the Milky Way. It was created when a star that was much more massive than the Sun exploded, an event that would have been visible from the Southern Hemisphere of the Earth over 1000 years ago.Chandra first observed E0102 shortly after its launch in 1999. New X- ray data have now been used to create this spectacular image and help celebrate the ten-year anniversary of Chandra’s launch on July 23, 1999. In this latest image of E0102, the lowest-energy X-rays are colored orange, the intermediate range of X-rays is cyan, and the highest-energy X-rays Chandra detected are blue. An optical image from the Hubble Space Telescope (in red, green and blue) shows additional structure in the remnant and also reveals foreground stars in the field.

The Chandra image shows the outer blast wave produced by the supernova (blue), and an inner ring of cooler (redder) material. This inner ring is probably expanding ejecta from the explosion that is being heated by a shock wave traveling backwards into the ejecta. A massive star (not visible in this image) is illuminating the green cloud of gas and dust to the lower right of the image. This star may have similar properties to the one that exploded to form E0102.

- Adapted from Material taken from NASA news annoucement


Tags: ,
Posted in Space Exploration, stars | 7 Comments »

Megascopes Watch Jupiter’s Black Eye

Written by The Night Sky Guy on July 22, 2009 – 9:35 pm -

This infrared image taken with Keck II shows the new feature observed on Jupiter and its relative size compared to Earth.

This infrared image taken with Keck II shows the new feature observed on Jupiter and its relative size compared to Earth.

Major observatories on the ground and in space are clamoring to get closeup views of the new impact on Jupiter that was first detected by an accomplished backyard astronomer in Australia on Monday (see earlier blog entry).  NASA scientists are hoping to get Hubble Space Telescope’s eye trained on the dark scar in Jupiter’s atmosphere late Wednesday and reports say that images may be released before the end of this week. Meantime the world’s largest monster-sized telescope – The Keck observatory, with its 10 meter diameter mirror, took a snapshot of the planet’s new bruise late Monday. Check out this amazing photo taken by Keck in the infrared.

In a NY Times report yesterday a Berkeley astronomer was quoted as saying that, “the shape of the debris splash as revealed in the Keck images suggested that whatever hit Jupiter might have been pulled apart by tidal forces from the planet’s huge gravity before it hit. In an e-mail message, he said humans should be thankful for Jupiter.

“The solar system would have been a very dangerous place if we did not have Jupiter,” he wrote. “We should thank our giant planet for suffering for us. Its strong gravitational field is acting like a shield protecting us from comets coming from the outer part of the solar system.”


Posted in Uncategorized | 215 Comments »

Radio Show: Guide to Satellite Hunting

Written by The Night Sky Guy on July 22, 2009 – 3:34 pm -

Coming up on my next CBC Radio One column today (Wednesday) we talk about spotting satellites above your backyard and how to conduct your own satellite hunting expedition. Tune in to the drive-home show between 3 pm and 6 pm on your city’s local CBC Radio One station.

Here are some online resources that can help you further explore satellites from your computer and backyard.

Space.com article on how to spot various manmade objects in the sky
NASA has its own SkyWatch page for catching satellites
NASA produced LIVE Tracking Chart of orbiting satellites
Read my recent blog entry on how to read those viewing charts
How-to article and 101 guide on finding iridium flares


Tags: , ,
Posted in Satellites | 227 Comments »