Space and astronomy news
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”
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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
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.
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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.
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
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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
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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
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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.
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.
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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
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Venus is the second planet from the Sun, and considered in many ways to be a twin planet of Earth. It has a similar size, mass, density and gravity, as well as a very similar chemical composition. In other ways, Venus is very different than Earth, with its high surface temperature, crushing pressure, and poisonous atmosphere. Let’s take a look at some of the characteristics of Venus.
As I said at the beginning, Venus is the second planet from the Sun. It orbits at an average distance of 108 million km from the Sun, taking almost 225 days to complete one revolution around the Sun. One of the strange characteristics of Venus is that it’s actually rotating backwards from the rest of the planets. Seen from above, all of the planets rotate counter-clockwise, but Venus turns clockwise on its axis. Even stranger, a day on Venus lasts 243 days, which is longer its year.
In terms of size, Venus is quite similar to Earth. Its radius is 6,052 km (95% the size of the Earth). Its volume is about 86% the volume of Earth, and its mass is 4.87 x 1024 kg, which is about 82% the mass of the Earth. The gravity on Venus is 90% the gravity on Earth, so if you could actually walk around on the surface of Venus, the gravity would feel very similar to Earth.
It’s when you get to the atmosphere of Venus that you see that the planet is very different from Earth. The temperature on the surface of Venus is a blistering 462 °C. That’s hot enough to melt lead! Furthermore, the atmospheric pressure on the surface of Venus is 92 times Earth pressure. You would have to travel a kilometer down beneath the surface of the ocean on Earth to feel that kind of pressure here. Venus’ atmosphere is composed almost entirely of carbon dioxide (97%), and it’s this thick atmosphere that acts like a blanket, keeping Venus so hot.
Venus has no water on its surface, and very little water vapor in its atmosphere. Scientists think that the runaway greenhouse effect that makes Venus so hot today boiled away its oceans long ago. Since Venus lacks a planetary magnetic field, the Sun’s solar wind was able to blast the hydrogen atoms out of Venus’ atmosphere and into space. Venus can never be cool again.
Most of the surface of Venus is covered by smooth volcanic plains, and its dotted with extinct volcanic peaks and impact craters. Venus has much fewer impact craters than other planets in the Solar System, and scientists have estimated that some event resurfaced Venus between 300-500 million years ago, wiping out all of the old impact craters and volcanoes.
Venus has no moons or rings.
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.
Reference:
NASA Solar System Exploration: Venus
Venus might look like a virtual twin of the Earth in terms of size, but its temperature and atmosphere make it very different from the Earth. The temperatures can reach almost 500°C, and the atmospheric pressure is almost 100 times what you would experience on the surface of Earth. With such a terrible environment, you might be surprised to know that spacecraft have landed on Venus (although, they sure didn’t last long).
The first spacecraft to enter the atmosphere of Venus was the Soviet Venera 3 probe, which crash landed on March 1, 1966. It was destroyed in the upper atmosphere, so it wasn’t able to return any useful information back to Earth.
The next spacecraft to attempt a landing on Venus was the Soviet Venera 4 spacecraft, which entered the atmosphere on October 18, 1967. Venera 4 was able to deploy several science experiments and was operating them as it passed down through Venus’ atmosphere. But mission planners didn’t realize that the atmosphere of Venus was so thick, and so it ran out of battery power about 25 km above the surface of Venus. But this failure helped missions planners better understand conditions on Venus.
The Venera 7 spacecraft was built to handle 180 times Earth atmospheric pressure, and used a special parachute to drop it down quickly through the atmosphere. It’s believed that the parachute partially failed, and so it impacted the surface of Venus hard. It was only able to return temperature data back to Earth for about 20 minutes.
Venera 8 survived for 50 minutes on the surface of Venus, sending back data.
But the first photographs taken from the surface of Venus were sent back by the Venera 9 and 10 spacecraft. Venera 9 landed on the surface of Venus on October 22, 1975 and operated on the surface of Venus for 53 minutes. It sent back the first images ever captured from the surface of Venus. Venera 10 landed on October 25th, and captured images of pancake-shaped lava rocks. Venera 10 lasted for 65 minutes, and was able to see farther into the distance than Venera 9.
But the most successful Venus landings were the Soviet Venera 13 and 14, which touched down on March 1st and March 5th, 1982. They both survived for over an hour, and returned the first color images ever captured from the surface of Venus.
All of the spacecraft that ever landed on Venus are probably still there today.
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.
If you’d like more information on Venus, check out 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.
Reference:
NASA Solar System Exploration: Missions to Venus
NASA: Mission to Venus Timeline
NASA Planetary Science: Mission to Venus