Fraser Cain, Author at Universe Today

November 28, 2007December 26, 2015 by Fraser Cain

Lightning Storms Seen on Venus

Venus is a hostile world, with high temperatures, intense pressures, and an atmosphere with sulphuric acid. The Russian spacecraft sent to explore it succumbed in mere hours. Well, now it appears that Venus is even more dangerous than previously imagined, with lightning flashing in the atmosphere.

This latest discovery was made using ESA’s Venus Express spacecraft, currently orbiting our evil twin planet. In a recent article published in the November 29th issue of the journal Nature, planetary geologists describe the lightning storms that flare across the planet.

And these storms aren’t rare. In fact, the scientists think that Venus has more lightning activity than we have here on Earth.

The source of the lightning is different, though. Here on Earth (and Jupiter and Saturn), the electrical energy comes from clouds made up of water vapour. On Venus, however, it’s those clouds of sulphuric acid that generate the electrical charge.

The discovery was made with the Venus Express magnetometer instrument on board the spacecraft. It took measurements once a day for two minutes, when the spacecraft was closest to the planet.

With Venus Express’ primary mission now complete, scientists are expanding its mission to other scientific questions, such as trying to spot infrared radiation from lava flows on the planet’s surface. In 2010, another spacecraft will arrive at Venus: the Japanese Venus Climate Orbiter. Scientists will then be able to compare observations between the two spacecraft.

And any future landers will need to be hardened against these lightning strikes, just in case they happened to descend through a lightning storm.

Original Source: NASA News Release

November 28, 2007January 24, 2021 by Fraser Cain

Astrosphere for November 28th, 2007

For your space photo, here’s a cool image captured by Gob332. It’s some star trails behind the branch of a tree.

The New York Times has a fascinating look at the space game Eve: Online. When I get tired of World of Warcraft, I’m sure I’ll give this a look.

Why explore space? The Bad Astronomer tells you why. Oh, and he’s also giving away a book.

When there’s private space travel, there’ll be space travel agents.

Remember that cool exoskeleton in Aliens? Reality is catching up fast.

Solar? Bio-fuel? Old technology ideas. Check out these cutting edge alternative energy concepts.

Pamela continues to debunk the speculative stories coming out of New Scientist. This time, that there’s an alternative universe poking through a void in space.

Chair Force Engineer shares his list of technologies that need to be developed for a spacefaring society.

November 27, 2007December 26, 2015 by Fraser Cain

New Images of the Martian Moons: Phobos and Deimos

With a fleet of spacecraft orbiting Mars, and rovers crawling across its surface, there’s a flood of images of the Red Planet. It’s nice to know the scientists working on those missions can take the time to look elsewhere every now and then. So today, let me present to you some images of the Martian moons: Phobos and Deimos.

The two images of the Martian moons were captured by the Compact Reconnaissance Imaging Spectrometer for Mars on board NASA’s Mars Reconnaissance Orbiter. Both images were captured while spacecraft was over Mars’ night side, and the ground below was dark.

In order to reorient away from Mars to view the moons, MRO had to turn off its normal nadir-viewing geometry.

The image of Phobos (on the top) was captured on October 23, and shows features as small as 400 metres (1320 feet) across. The image of Deimos was captured on June 7, and shows features as small as 1.3 km (0.8 miles) across.

Phobos is only 21 km (13 miles) across, and orbits Mars once every 7 days, 39 minutes. Because the moon orbits Mars faster than it rotates, Phobos would appear to travel backwards across the sky from an observer on the ground. This is just an illusion, though. Even though it’s tiny, Phobos orbits so closely that it would appear to be 1/3rd the size of our own moon in the sky.

Deimos is even smaller – 12 km (7.5 miles) – but it orbits more distantly than Phobos. It takes 1 day, 6 hours and 17 minutes to orbit the planet. Deimos isn’t large enough that you could make out any features from the surface of Mars. Instead, it would just look like a bright star in the night sky.

The first ever spacecraft observations of the Martian moons were made by Mariner 9 and the Viking Orbiter spacecraft. They found the moons to have very low reflectivity, and appeared to be similar in structure to carbonaceous chondrite meteorites. This led to the commonly held view that the moons are captured asteroids.

Original Source: MRO News Release

November 27, 2007December 26, 2015 by Fraser Cain

Scientists Compile a Detailed Map of Antarctica

Satellites have revolutionized climate science and geology. The better your instruments, the better you can track what’s actually going on around the world. This week US and British science agencies unveiled the output of some of these instruments: a detailed map of Antarctica.

The new map of Antarctica is a mosaic of images captured by NASA satellites over years of observations. Scientists from the National Science Foundation, the U.S. Geological Survey and NASA worked with the British Antarctic Survey to hand-select the best individual images. The completed mosaic offers a cloudless view of the frozen continent’s surface at a resolution 10 times better than anything seen before.

The full mosaic contains more than 1,100 separate images stitched together from three years of Landsat observations. NASA has made the full images and data available to the public from a free web portal, and has 8 different versions of the full mosaic available for download. The homepage has a cool way to drag the map around, like Google Maps (although, I couldn’t get it to work).

The researchers are hoping this will give scientists a detailed snapshot of the current state of Antarctica, including its various ice sheets which contain 60% of the Earth’s fresh water.

Original Source: NSF News Release

November 27, 2007December 26, 2015 by Fraser Cain

Comet Holmes is Fading Away

For a little while there, Comet 17P/Holmes was the largest object in the Solar System, flaring up by a factor of over a million. Its cloud of gas and dust expanded outward to cover a diameter of 1.4 million km (870,000 miles) – bigger than the Sun. Well, the party’s over. Comet Holmes is fading away again. But will it follow history and flare up again?

This image of Comet Holmes was captured by the MMT observatory on November 4th, 2007 using an instrument called “Megacam”. This is one of the largest CCD cameras on Earth, putting 36 9-megapixel CCD chips together to form a single array with 300 megapixels.

The camera captured images of the comet with three separate exposures in three colours to produce this full colour image.

If you want to see Holmes before it fades into obscurity again, you’re going to need binoculars. Although it’s still a 3rd magnitude object, and should be visible with the unaided eye, it’s so large in the sky that it’s actually quite faint now.

Astronomers are hoping that it’ll repeat history. During its last outburst back in 1892, the comet underwent a second bright flareup five months after the first one. So, if history is any judge, we might just see the comet brighten again, and we’ll all get another chance to see it before it’s gone for good.

Original Source: CfA News Release

November 27, 2007January 24, 2021 by Fraser Cain

Astrosphere for November 27th, 2007

First, let me direct your attention to the 30th Carnival of Space, hosted by Bad Astronomy. I don’t want to sound like a broken record here, but the Carnival is a great way to increase exposure to your website or blog. If you want more readers, join the carnival.

My absolute favourite television show, Futurama, has a new DVD coming out called Bender’s Big Score. If you like the show, give it some support and buy a DVD. You can find out more here from the official website.

Centauri Dreams talks about the past and future of solar sail technology.

Astronomy Picture of the Day has this image of the International Space Station over the Ionian Sea. Just think what it took to capture that image.

Colony Worlds reports on a new technology that could give solar energy the ability to keep on providing power, right through the night.

Astroprof offers you an easy way to find Mars; just look for the Moon. The two objects are close together right now, and easy to find.

Pamela Gay debunks the recent news that observing the Universe will hasten its demise.

November 26, 2007December 26, 2015 by Fraser Cain

Pure Carbon Stars Discovered

When stars like our Sun run out of fuel, they die a long slow death as a white dwarf, slowing cooling down over billions of years. But now an international team of astronomers has found an unusual form of white dwarf with a bare carbon core; one that might suggest a new sequence of stellar evolution. A fate for stars right on the edge of detonating as supernovae.

The majority of stars that die eventually become white dwarfs in the end. The most massive 2-3% of stars will actually detonate as supernovae when they end their lives. But these newly discovered objects might have been right at the borderline. If they were just a little more massive, they would have detonated as well, but instead, they didn’t quite make it.

The evidence was gathered by astronomers from the University of Arizona, UniversitÃ© de MontrÃ©al and Paris Observatory. They reviewed more than 10,000 new white dwarfs found in the most recent update to the Sloan Digital Sky Survey. This automated survey has turned up four times as many white dwarf stars as previously known.

As stars run out of hydrogen, they switch to helium, and as this burns off, they’re left with a core of carbon and oxygen surrounded by an atmosphere of hydrogen or helium. That’s what a normal white dwarf looks like.

But a small group of these white dwarfs have a very bizarre appearance. They’re just a bare core of carbon, without any surrounding atmosphere of hydrogen or helium.

From the press release announcing the discovery, researcher Patrick Dufour describes the discovery, “when I first started modeling the atmospheres of these hotter DQ stars, my first thought was that these are helium-rich stars with traces of carbon, just like the cooler ones. But as I started analyzing the stars with the higher temperature model, I realized that even if I increased the carbon abundance, the model still didn’t agree with the SDSS data. Out of pure desperation, I decided to try modeling a pure-carbon atmosphere. It worked. I found that if I calculated a pure carbon atmosphere model, it reproduces the spectra exactly as observed. No one had calculated a pure carbon atmosphere model before. No one believed that it existed. We were surprised and excited.”

The researchers believe you need to have a star with 9-11 solar masses to create a carbon star like this. They’re planning follow up observations to better pinpoint the masses of the objects they’ve discovered so far.

Original Source: UA News Release

November 23, 2007December 26, 2015 by Fraser Cain

Inflatable Lunar Habitat to Be Tested in Antarctica

As humans prepare to return to the Moon, this time to stay, there are so many different technologies that need to be developed and tested. NASA and the NSF are testing out a new prototype for an inflatable habitat that might eventually protect humans on the Moon. And they’re testing it in the most extreme place on Earth: Antarctica.

The newly developed inflatable habitat is inflated and pressurized, giving potential astronauts their own atmosphere. Inside the tent is heated, offering up 35 square metres (384 square feet) of living space, under a 2.4-metre (8-foot) ceiling. It also has access points for electrical power.

NASA currently uses a 50-year old tent design called a Jamesway hut. Television viewers will recognize these designs in the show M*A*S*H. Although there are new approaches to this old design, they’re rigid, difficult to ship, and have limited insulation. When you’re working in Antarctica, a lack of insulation is a serious problem.

The purpose of this new design is to test out how well an inflatable habitat will work in terms of packing, transportation, set up, power consumption and damage tolerance.

When astronauts do finally return to the Moon by 2020, they’ll be setting up a permanent lunar outpost. An inflatable habitat like this could be carried on future lunar rovers, and would allow the astronauts to set up a temporary home, far away from the permanent base. This would greatly increase their range, and allow the exploration of the most interesting lunar features – not just those nearby the base.

The inflatable habitat is being developed under NASA’s Innovative Partnerships Program.

Original Source: NSF News Release

November 16, 2007December 26, 2015 by Fraser Cain

Astrosphere for November 16th, 2007

Today’s photo is the Moon. Sure, I’ve shown lots of pictures of the Moon, but this one’s lunertic’s first astrophoto, and I thought I could help encourage this wonderful hobby. Take more, let’s see them.

Space Prizes has some interesting links to the recent 2009 Space Settlement Calendar Art Contest. How come nobody told me about this?

Nancy Houser at A Mars Odyssey has a great two part article about the first African American astronaut: Guion Bluford. Here’s part 1 and part 2.

Astronomy Picture of the Day has an image of the Orion Nebula, with a streak through the middle that turned out to be fuel dumped out of a recent rocket launch.

Jeff Foust at Space Politics gives a run down of NASA’s Administrator’s time in front of a Senate committee. It sounds like an uncomfortable place to be. Keith Cowing from NASA Watch has an opinion on the matter too.

Director of the Planetary Society, Louis Friedman, puts the most recent shuttle mission into perspective. The astronauts had a dangerous job of fixing the station’s solar wings, so why wasn’t there more press about it?

Pamela Gay translates some astro-gibberish into a really interesting scientific result.

The Angry Astronomer got a great post about the power of Big Sky Surveys.

November 15, 2007December 26, 2015 by Fraser Cain

Prototype Heat Shield for Orion

I know what you’re thinking, and no, that’s not a UFO in a secret government laboratory. It’s not a prop for an upcoming science fiction movie, and it’s not the world’s largest Frisbee. It’s a prototype heat shield, developed by Boeing for NASA’s Orion Crew Exploration Vehicle.

When Orion returns from space, it needs to decelerate from orbital velocity to be able to land safely. Just like the space shuttle, the capsule will point this heat ablating surface into the atmosphere, and let it get super hot. The heat shield can rise to extremely high temperatures, while the astronauts stay nice and safe.

The lunar protective system will need to be much more capable that the shuttle’s system, since capsules will be returning directly to the Earth after flying from the Moon. In some cases, Orion’s thermal protection will face 5 times as much heat as vehicles returning from the International Space Station. That’s hot.

It was the catastrophic failure of Columbia’s heat shield that doomed it when it was re-entering the Earth’s atmosphere. Needless to say, NASA wants to get this right.

The contract for the new Thermal Protection System was awarded to Boeing Advanced Systems about a year ago. Last month, a NASA Ames technical and quality inspection team completed an acceptance review of the shield.

The shield is made from Phenolic Impregnated Carbon Ablator (PICA). That’s a mouthful, but it uses a special trick to keep the capsule cool. As the heat shield heats up during reentry, the PICA material “ablates”. It chars, melts and then sublimates to create a cool boundary layer that protects the spacecraft.

Boeing will continue working on the heat shield, to meet Orion’s TPS preliminary design review in early 2008.

Original Source: Boeing News Release