Universe Today

August 5, 2009December 24, 2015 by Anne Minard

Spitzer Changes Its Glasses, Sees Cotton Candy

Infrared picture of a cloud, known as DR22, bursting with new stars in the Cygnus region of the sky.

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The Spitzer Space Telescope has run out of the liquid helium that kept its optics cool — but the scope has already returned compelling new images as if to say:

I don’t need no stinkin’ helium.

At five and a half years, Spitzer’s prime mission more than doubled initial expectations. It finally ran out of liquid helium in May and was retooled for a new “warm mission” that began July 27. With its two remaining infrared channels, the telescope promises to observe with roughly the same sensitivity as a 30-meter ground-based telescope.

The lead infrared image shows the dying star NGC 4361, which was once hot like our Sun before it puffed out.

This next one shows dusty gas in blue and hot clouds in orange in DR22, a cloud bursting with new stars in the Cygnus region of the sky.

Spitzer's infrared eyes can both see dust and see through dust. The blue areas are dusty clouds, and the orange is mainly hot gas.

The new images were snapped with the two infrared channels that still work at Spitzer’s still-quite-chilly temperature of 30 Kelvin (about minus 406 degrees F). The two infrared channels are part of Spitzer’s infrared array camera: 3.6-micron light is blue and 4.5-micron light is orange.

This last picture shows a relatively calm galaxy called NGC 4145, 68 million light-years away in the constellation Canes Venatici.

Barred Spiral Galaxy NGC 4145, 68 million light-years away in the constellation Canes Venatici.

All of The new pictures were taken while the telescope was being re-commissioned, on July 18 (NGC 4145, NGC 4361) and July 21 (Cygnus), 2009.

Since its launch from Cape Canaveral, Florida on Aug. 25, 2003, Spitzer has made many discoveries. They include planet-forming disks around stars, the composition of the material making up comets, hidden black holes, galaxies billions of light-years away and more.

Perhaps the most revolutionary and surprising Spitzer finds involve planets around other stars, called exoplanets. In 2005, Spitzer detected the first photons of light from an exoplanet.

Warm Spitzer will address many of the same science questions as before. It also will tackle new projects, such as refining estimates of Hubble’s constant, or the rate at which our universe is stretching apart; searching for galaxies at the edge of the universe; characterizing more than 700 near-Earth objects, or asteroids and comets with orbits that pass close to our planet; and studying the atmospheres of giant gas planets expected to be discovered soon by NASA’s Kepler mission.

“The performance of the two short wavelength channels of Spitzer’s infrared array camera is essentially unchanged from what it was before the observatory’s liquid helium was exhausted,” said Doug Hudgins, the Spitzer program scientist at NASA Headquarters in Washington.

Credit for all images: NASA/JPL-Caltech

Source: NASA’s Spitzer site and a press release through the American Astronomical Society (AAS).

August 5, 2009December 24, 2015 by Nancy Atkinson

Where In The Universe #65

Here’s this week’s image for the WITU Challenge, to test your visual knowledge of the cosmos. Take a look at this image and see if you can determine where in the universe this image is from. This one is a little different, but several readers sent it in, suggesting we use it. We’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.

UPDATE: The answer has now been posted below.

This is a model of an exploding star’s core created by the U.S. Department of Energy’s Argonne National Laboratory developed to help show what happens inside core-collapse supernovae. The model was made using the lab’s IBM Blue Gene/P machine, currently ranked seventh on a list of the world’s most powerful supercomputers. Argonne’s Blue Gene/P boasts more than 160,000 processors, as many as would be found in Giants Stadium were it filled to capacity with people toting dual-core laptops.

To find out more about this images see this article in Scientific American.

August 5, 2009April 26, 2016 by Anne Minard

Hubble, Gemini Spot ‘Hyperactive’ Stars in Small, Young Galaxies

We all know youngsters are a handful, but this really takes the cake: astronomers have clocked the speeds of stars in infant galaxies at about a million miles an hour, about twice the pace of our Sun’s cruise through the Milky Way.

The small galaxies date to 11 billion years ago, when the universe was just a couple billion years old. Their stars, astronomers say, are buzzing and whirling at head-spinning rates.

Continue reading “Hubble, Gemini Spot ‘Hyperactive’ Stars in Small, Young Galaxies”

August 5, 2009December 24, 2015 by Nancy Atkinson

There Was a Reason Discovery’s Rollout Took Longer Than Usual…

Lightning flashes during Discovery's rollout on Tuesday. Credit: NASA

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Yikes! No wonder the rollout of space shuttle Discovery took a little bit longer than usual. Lightning lit up the sky above Kennedy Space Center early Tuesday morning, providing a stunning backdrop for the shuttle’s crawl to the launchpad. Usually the trip takes about six hours, but various weather-related concerns slowed the move out past 11 hours. Lightning delayed Discovery’s exit from the Vehicle Assembly Building for about 2 hours, and then mud from recent thunderstorms forced the crawler to stop repeatedly so engineers could clean out the giant treads on the huge 5.5 million-pound (2.4 million-kg) vehicle that hauls shuttles out to the launch pad. Discovery is scheduled to launch on August 25 for the STS-128 mission to the ISS. Of interest is that this mission will bring the C.O.L.B.E.R.T treadmill to the station, an exercise device named after comedian Stephen Colbert.

Discovery will carry the Leonardo supply module to the International Space Station during STS-128, along with several refrigerator-sized racks with equipment and supplies, and a new crew member for the station, Nicole Stott. The mission will be commanded by veteran astronaut Rick “C.J.” Sturckow, along with Pilot Kevin Ford and Mission Specialists Patrick Forrester, Jose Hernandez, John “Danny” Olivas and Sweden’s Christer Fuglesang.

Source: NASA

August 5, 2009December 24, 2015 by Anne Minard

New View Toward Carina Reveals Star Fest, Exploding “Engine”

A remarkable new view of the Milky Way toward the constellation Carina is alive with a flurry of stars — and the pièce de résistance is a binary star that’s all dressed up in a nebula of its own making.

The European Southern Observatory (ESO) released the new images this week.

The unusual star, HD 87643, has been extensively studied with several ESO telescopes, including the Very Large Telescope Interferometer (VLTI). Surrounded by a complex, extended nebula that is the result of previous violent ejections, the star has been shown to have a companion. Interactions in this double system, surrounded by a dusty disc, may be the engine fueling the star’s remarkable nebula.

HD 87643 is at the center of the extended nebula of dust and gas on the first image, obtained with the Wide Field Imager on the ESO/MPG 2.2-meter (7.2-foot) telescope at La Silla Observatory in Chile. The central panel is a zoom on the star obtained with NACO on ESO’s VLT on Paranal. The last panel zooms further , showing an image obtained with the AMBER instrument making use of three telescopes of the VLTI. The field of view of this last panel is less than one pixel of the first image.

HD 87643 is a member of the exotic class of B[e] stars — luminous, powerful blue stars with strong spectral evidence of hydrogen. The new image is part of a set of observations that provide astronomers with the best ever picture of a B[e] star.

The central star’s wind appears to have shaped the surrounding nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years.

A team of astronomers, led by Florentin Millour of the Max-Planck Institute for Radio Astronomy in Bonn, Germany, has studied the star HD 87643 in great detail.

The sheer range of the observations, from the panoramic WFI image to the fine detail of the VLTI observations, corresponds to a zoom-in factor of 60,000 between the two extremes. The astronomers found that HD 87643 has a companion located at about 50 times the Earth–Sun distance and is embedded in a compact dust shell. The two stars probably orbit each other in a period between 20 and 50 years. A dusty disc may also be surrounding the two stars.

The presence of the companion could be an explanation for the regular ejection of matter from the star and the formation of the nebula: as the companion moves on a highly elliptical orbit, it would regularly come very close to HD 87643, triggering an ejection.

Source: European Southern Observatory (ESO). Check the site for more images and a video. A paper about the results is here.

August 4, 2009December 24, 2015 by Nancy Atkinson

Ares I-X Comes Together (and it is BIG)

The Ares I-X is stacked in NASA's Vehicle Assembly Building. Credit: NASA

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The Ares I-X rocket is being stacked on the Mobile Launch Platform in NASA’s Vehicle Assembly Building in preparation for the rocket’s first test flight, scheduled for October 31, 2009. The “super stack 1” was mated to the forward motor segment, and the rocket — which will stand at 99 meters (327 feet) — is now more than half way assembled. Assembly is done using a massive overhead crane, specially adapted for I-X use.

For comparison, the space shuttle stands at 56.1 m (184 ft), the Saturn V rocket was 110.6 m (363 ft), and the Ares V will be 116 m (380 ft) high.

See more images of the rocket below.

According to NASA’s Ares Blog, super stack 1 is composed of the fifth segment simulator, forward skirt, forward skirt extension, frustum and interstages 1 and 2. It also includes two internal elements – the roll control system and the first stage avionics module – as well as the parachute system housed in the forward skirt extension.

The Ares I-X flight test will provide NASA an opportunity to check and prove hardware, analysis and modeling methods, and facilities and ground operations needed to develop the Ares I, which currently is NASA’s next crew launch vehicle. However, President Obama has assembled the Augustine Commission to evaluate the Ares rocket and the entire Constellation Program to determine if NASA should continue on its current path.

The test also will allow NASA to gather critical data during the ascent of the integrated stack, which will help inform the design of the Ares I rocket and the Orion crew exploration vehicle. The data will ensure the entire vehicle system is safe and fully operational before astronauts begin traveling in it to the International Space Station and moon.

Another view of the Ares I-X being assembled. Credit: NASA

Over the next month, four more super stacks with the final pieces of hardware (including the simulated crew module and launch abort system) will be mated, finishing off the stacking operations for the rocket.

Source: Ares Blog

August 4, 2009January 24, 2021 by Nancy Atkinson

LCROSS Sees Life on Earth

LCROSS UV/Visible spectrum. Credit: NASA

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The LCROSS spacecraft took a look back at Earth, and guess what it saw? Evidence of intelligence? Not so much. But it did see evidence of life. On Aug. 1, 2009, the LCROSS spacecraft took a gander at Earth to help calibrate and test its science payload. During the Earth observations, the spacecraft’s spectrometers were able to detect the signatures of the Earth’s water, ozone, methane, oxygen, carbon dioxide and possibly vegetation.

Phil Plait explained on Bad Astronomy that this spectrum covers part of the ultraviolet and visible range of light, and this type of observation with better instruments in the future could help us find life on other planets. Phil wrote. “You can see that LCROSS clearly detected ozone (O3) and water, which you might see on any old planet. But it also saw a feature that is from free oxygen (O2), something you don’t see just anywhere .… The only reason we have a lot of it in our air (more than 20% of the Earth’s atmosphere is O2) is because we have life in the form of plants.” Check out Phil’s post here.

The spacecraft also took these images of Earth, again, helping to refine camera exposure settings, check instrument pointing alignment, and check radiometric and wavelength calibrations.

LCROSS is in an elongated Earth orbit, and on course to impact the Moon’s south pole in October. From its current vantage point of 223,700 miles (360,000 km) from Earth, the LCROSS science team changed exposure and integration settings on the spacecraft’s infrared cameras and spectrometers and performed a crossing pattern, pushing the smaller fields of view of the spectrometers across the Earth’s disk. At this range, the Earth was approximately 2.2 degrees in diameter.

“The Earth-look was very successful,” said Tony Colaprete, LCROSS project scientist. “The instruments are all healthy and the science teams was able to collect additional data that will help refine our calibrations of the instruments.”

An additional Earth-look and a moon-look are scheduled for the remainder of the cruise phase of the mission.

Sources: NASA, Bad Astronomy

August 4, 2009December 24, 2015 by Nancy Atkinson

First Tweets from the ISS

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Listen my children and you shall hear
Tweets coming from up above our Earthly sphere.

The newest International Space Station astronaut has started Tweeting from space. Tim Kopra is the first ISS crew member to use the social media tool Twitter to discuss living and working in orbit. Kopra (@Astro_Tim) recently joined the Expedition 20 crew after arriving July 17 aboard space shuttle Endeavour. But the coolest thing is that his first Tweets’ origin was “from Mobile Web.” Yep, from the ISS, that’s really mobile.

But of course, there isn’t really “the web” up on the space station. But Kopra will sent down his Tweets messages to mission control in Houston, and they will post them on Twitter.
NASA says Kopra will provide followers with a unique perspective as an Expedition 20 flight engineer and member of the Army. He is an Army aviator and West Point graduate. He periodically will answer questions submitted on the Army’s Web site. To submit questions and view Kopra’s answers, visit the US Army’s website

This is Kopra’s first spaceflight. He completed his first spacewalk July 18 during the STS-127 mission. Kopra is in orbit with station Commander Gennady Padalka and Roman Romanenko — both Russian cosmonauts — and NASA astronaut Mike Barratt, European Space Agency astronaut Frank DeWinne and Canadian Space Agency astronaut Bob Thirsk.

As of this writing, Astro_Tim has close to 5,000 followers.

You can also follow Universe Today and Nancy on Twitter.

Source: NASA

August 4, 2009December 24, 2015 by Nancy Atkinson

Plains of Titan to be Named for “Dune” Novels

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Titan’s mysterious dark plains will be named after planets in the series of “Dune” science fiction novels by author Frank Herbert. The US Geological Survey Astrogeology Science Center announced the first plain or “planitia” given a name will be designated as Chusuk Planitia. Chusuk was a planet from the Dune series, known for its musical instruments. Chusuk Planitia on Titan is located at 5.0S, 23.5W, and in the picture here is the small, dark area next to the “C” of Chusuk.

Download a large map of Titan with the named features (pdf file).

The Cassini spacecraft has enabled us to finally see these dark plains on Titan. This moon is enveloped by an orange haze of naturally produced photochemical smog that frustratingly obscured its surface prior to Cassini’s arrival. Since 2004, the spacecraft’s observations have taken the study of this unique world into a whole new dimension.

Crescent Titan. Credit: NASA/JPL/Space Science Institute

One of Cassini’s latest images of Titan looks down on the north pole of Titan, showing night and day in the northern hemisphere of Saturn’s largest moon.

This view is centered on terrain at 49 degrees north latitude, 243 degrees west longitude. The north pole of Titan is rotated about 23 degrees to the left and it lies on the terminator above and to the left of the center of the image. Titan is 5,150 kilometers, or 3,200 miles across.

This natural color image was created by combining images taken with red, green and blue spectral filters. The images were obtained with the Cassini spacecraft wide-angle camera on June 6, 2009 at a distance of approximately 194,000 kilometers (121,000 miles) from Titan. Image scale is 11 kilometers (7 miles) per pixel.

Titan is one of the most Earth-like world we have found in our solar system. With its thick atmosphere and organic-rich chemistry, Titan resembles a frozen version of Earth, several billion years ago, before life began pumping oxygen into our atmosphere.

Cassini has revealed that Titan’s surface is shaped by rivers and lakes of liquid ethane and methane which forms clouds and occasionally rains from the sky as water does on Earth. Winds sculpt vast regions of dark, hydrocarbon-rich dunes and plains around Titan’s equator and low latitudes.

Source: USGS, Cassini website.

Hat tip to Emily Lakdawalla!

August 4, 2009December 24, 2015 by Fraser Cain

Earth’s Twin

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Scientists call Venus Earth’s twin planet and for good reason. Our two planets are similar in size, mass, density, gravity, and composition. Of course, they have some enormous differences as well; differences that would kill you instantly if you tried to step foot on Earth’s twin planet. Earth’s evil twin planet, maybe.

Let’s look at the similarities first. For starters, the size of Venus is very close to Earth. The diameter of Venus is 12,103.6 km. That’s only 95% of the Earth’s diameter of 12,756.2 km. If you put the two planets side by side, you’d have a hard time telling which one’s bigger.

The volume of Venus is 85.7% the volume of Earth, and it has 90% of the Earth’s surface area. The mass of Venus is 81.5% the mass of the Earth, and even the force of gravity is only 90% of what you experience here on Earth.

The composition of the two planets is similar too. Both have metal cores surrounded by a mantle of silica rock, and then a thin crust. There are some differences here, though. Earth’s core has convection which generates the planetary magnetic field, while Venus doesn’t have a similar magnetic field. Earth has plate tectonics, which help release heat from within the planet, while Venus doesn’t.

But there are bigger differences. And this is where it’s better to consider Venus as an evil twin planet. The temperature of Venus across the whole planet is 461.85 °C. That’s hot enough to boil lead! Spacecraft from Earth have only lasted a couple of hours at maximum because of the incredible temperatures. In fact, Venus is the hottest planet in the Solar System.

And if the temperature isn’t bad enough, the air pressure is even worse. The atmospheric pressure on the surface of Venus is 93 times higher than what you’d experience on Earth. In fact, you’d have to travel a kilometer beneath the surface of the ocean to experience that kind of pressure. While Earth’s atmosphere is made up of oxygen and nitrogen with trace amounts of carbon dioxide, Venus’ atmosphere is 96.5% carbon dioxide with the rest nitrogen. It has clouds of sulphuric acid that rain down to add to the planet’s lethality.

Earth has vast reserves of water, while Venus is almost completely dry. There are no reserves of water on the surface of Venus, and just a trace amount of water in its atmosphere. Because Venus doesn’t have a global magnetic field, it’s constantly pummeled by the Sun’s solar wind, which strips the lightest elements out of its atmosphere. Satellites have detected a constant stream of hydrogen atoms streaming away from Venus, lost from the planet forever.

And just one last difference, Earth has the Moon, but Venus has no moons. It might have had a moon in the past, but it’s believed to have crashed into the planet a long time ago.

We have written many articles about Venus for Universe Today. Here’s an article about Venus’ wet, volcanic past, and here’s an article about how Venus might have had continents and oceans in the ancient past.

Want more information on Venus? Here’s a link to Hubblesite’s News Releases about Venus, and here’s a link to NASA’s Solar System Exploration Guide on Venus.

We have recorded a whole episode of Astronomy Cast that’s only about planet Venus. Listen to it here, Episode 50: Venus.

References:
NASA Solar System Exploration: Venus
NASA Solar System Exploration: Earth