Universe Today

November 9, 2009May 4, 2017 by Fraser Cain

How Far is Saturn from the Sun?

Saturn’s distance from the Sun is 1.4 billion km. The exact number for Saturn’s average distance from the Sun is 1,433,449,370 km.

Need that number in miles? Saturn’s average distance from the Sun is 891 million miles.

Noticed that I said that these numbers are Saturn’s average distance from the Sun. That’s because Saturn is actually following an elliptical orbit around the Sun. Some times it gets closer, and other times it gets more distant from the Sun. When it’s at the closest point of its orbit, astronomers call this perihelion. At this point, Saturn is only 1.35 billion km from the Sun. Its most distant point in orbit is called aphelion. At this point, it gets out to 1.51 billion km from the Sun.

Astronomers use another measurement tool for calculating distance in the Solar System called “astronomical units”. 1 astronomical unit is the average distance from the Earth to the Sun; approximately 150 million km. At its closest point, Saturn is 9 AU, and then at its most distant point, it’s 10.1 AU. Saturn’s average distance from the Sun is 9.6 AU.

We have written many articles about Saturn for Universe Today. Here’s an article about how NASA’s Spitzer space telescope discovered a huge ring around Saturn, and here’s a cool movie of an aurora around Saturn.

If you want more information on Saturn, check out Hubblesite’s News Releases about Saturn. And here’s a link to the homepage of NASA’s Cassini spacecraft, which is orbiting Saturn.

We have also recorded an entire episode of Astronomy Cast just about Saturn. Listen here, Episode 59: Saturn.

November 9, 2009December 24, 2015 by Nicholos Wethington

Camera Network Spies Anomalous Meteorite

A network of time-lapse cameras set up in the Nullarbor Plain desert of Western Australia has allowed researchers to track a fallen meteorite to the ground, and enabled them to determine its original orbit and parent body. The meteorite has a composition different than that of other meteors, leading researchers to believe that it originates from a different parent body than most meteorites that impact Earth. The Desert Fireball Network, a project coordinated by the Imperial College of London, was able to track the meteor when it entered the atmosphere, giving researchers an impact location and information on where it originated.

The Bunburra Rockhole meteorite – so named for the location where it was discovered – fell to the Earth on July 20th, 2007. The Desert Fireball Network cameras recorded the fireball produced when the meteor passed through the Earth’s atmosphere, and by studying the entry angle of the meteor, researchers from the Imperial College were able to locate it on the ground. It was found within 100 meters (300 feet) of where they had predicted it to be.

This meteorite weighs 324 grams (12 oz), and is composed of a rare type of basalt igneous rock. More specific information on the meteorite itself can be found on the Meteorological Society’s index. Most meteorites of this composition come from one parent body, the asteroid 4 Vesta. However, the Bunburra Rockhole meteorite likely came from a different asteroid with a different orbit, which means that the formation process for the asteroid happened in a different place in the Solar System than for 4 Vesta.

The researchers determined that the Bunburra Rockhole originated from an asteroid located in the innermost main asteroid belt between Mars and Jupiter. Because the Desert Fireball Network captured images on multiple cameras of how it entered the Earth’s atmosphere, the researchers were able to triangulate the position of the rock, and model its orbit backwards in time to determine its origins.

Dr Gretchen Benedix of the Natural History Museum – where the largest fragment of the meteorite is located – analyzed the mineral content of the meteorite. She said in a press release:

“It’s vital to have a meteorite with information about where it comes from in the solar system…. We’ve known for a long time that most meteorites are from the asteroid belt, but we don’t know exactly where. This kind of information helps us fit one more piece in the puzzle of how the solar system formed and evolved. The fact that this meteorite is compositionally unusual increases it’s value even more. It helps us to uncover more information about the conditions of the early solar system.”

The Desert Fireball Network monitors the Nullarbor desert in Western Australia, and has tracked a total of 7 meteorites, three of which have been recovered. The desert is an excellent location for this type of project, as observing conditions are clear many nights out of the year, and the sparse vegetation and monotone landscape make finding the meteorites easier than in other locations.

The results of the meteorite mineral and orbital study are published in Science, and two previous papers about the Bunburra Rockhole are available on the Desert Fireball Network site.

Source: Natural History Museum, Imperial College of London

November 9, 2009April 26, 2016 by Nicholos Wethington

Why did HAL sing ‘Daisy’?

Okay, so this may not be important breaking news about astronomy, but it may answer a burning question posed by most people who have watched or read “2001: A Space Odyssey”: that is, why does the computer HAL-9000 sing the song ‘Daisy Bell’ as the astronaut Dave Bowman takes him apart? Well, Stanley Kubrick and Arthur C. Clarke made HAL’s final act in the world this song as a tribute to HAL’s great ancestor, the first IBM computer to ever sing. Click below for more on this geeky topic!

In 1962 Arthur C. Clarke, who wrote the novel – and co-wrote the screenplay for the movie – “2001: A Space Odyssey”, visited Bell Labs before putting the finishing touches on the work. There, he was treated to a performance of the song ‘Daisy Bell’ (or, ‘A Bicycle Built for Two’) by the IBM 704 computer. This evidently inspired him to have HAL sing the song as an homage to the programmers of the 704 at Bell Labs, John L. Kelly, Carol Lockbaum, and Max Mathews. Kelly and Lockbaum programmed the lyrics, and Mathews the accompaniment.

‘Daisy Bell‘ was originally composed in 1892 by Henry Dacre, and English composer. Upon coming to the U.S., he was charged a duty fee for his bicycle. A friend remarked that it was lucky that he didn’t bring a bicycle built for two, or he would have had to pay double duty. Taken by the phrase, he used in in a song to acclaim both before it became a smash hit with computers with a penchant for song, and after.

Here’s a recording of the 704 talking and singing the song. If you want to sing along karaoke style to the original singer, here’s a video of the 704 doing its ditty (ignore the different model name and year – the 7094 exists but can’t even sing backup):

And, of course, here is HAL-9000 in his death throes with a more maniacal version of the classic:

Source: Switched, MOG, Bell Labs

November 9, 2009December 24, 2015 by Nicholos Wethington

NASA and ESA Sign Mars Exploration Joint Initiative

NASA and the European Space Agency (ESA) have officially agreed to combine their efforts in the exploration and study of Mars. The heads of both agencies, NASA administrator Charles Boden and ESA director-general Jean-Jacques Dordain signed an agreement that officially binds the two agencies together for upcoming orbiter and rover missions. Discussions of this cooperation began in December of 2008, and culminated in a meeting in June 2009, out of which came the official agreement signed last week.

The new “letter of intent” outlines the Mars Exploration Joint Initiative (MEJI), under which mission engineers will cooperate in the design and launch of rovers, orbiters and landers into the 2020s, with the ultimate goal of returning rocks from Mars to Earth for study. The first collaborative mission is a European-led orbiter that will also place a meteorological station on Mars planned for 2016. This will be followed by surface rovers to keep Spirit and Opportunity company (c’mon, you know they’ll still be ticking!) in 2018, and possibly a network of landers shortly after in 2018, one of which will include the ESA’s ExoMars Lander.

NASA will take care of the launching rockets for 2016 and 2018, and the ESA will cover the entry, descent and landing for the first mission in 2016.

The signing of this document makes official the talks held in Plymouth, UK this past June. Since the talks, most of the fine print has been worked out on the collaboration – this signing just seals the deal.

The ESA and NASA, both under financial constraints in their Mars exploration programs, envision this new union to allow both to to launch vehicles in the window that opens every 26 months for missions to Mars. NASA’s most recently planned mission to the Red Planet, the Mars Science Laboratory, missed the October 2009 window because of technical problems, so will have to be launched in 2011 instead. The same fate befell the ESA ExoMars lander, which has been postponed three times – until 2018 – from the initial launch date of 2009. This joint initiative aims at preventing such delays by sharing both engineering and financial responsibilities.

NASA’s associate administrator for science, Dr Ed Weiler, told the BBC back in July,”We have very similar scientific goals, maybe we ought to consider working together jointly on all our future Mars missions, so that we can do more than either one of us can do by ourselves.”

Hopefully, this collaboration will provide both administrations with the opportunity to get more science done for cheaper, and extend further the already amazing capabilities of proposed missions to the Red Planet.

Source: BBC, ESA

November 9, 2009April 26, 2016 by Nancy Atkinson

Remembering Carl Sagan

Today would have been Carl Sagan’s 75th birthday. His life and work were monumental in astronomy and public outreach, and he had a profound influence on many people. I count myself among those who say they might not be where they are today were it not for Carl Sagan. Reading his books such as “Cosmos” and “Demon Haunted World” broadened my horizons when I needed it most. One of my favorite books of all time is “Pale Blue Dot” which really puts everything in perspective. Above is a video excerpt from the book.

If you choose, there are a few different ways you can remember Sagan and celebrate his life:
Continue reading “Remembering Carl Sagan”

November 8, 2009March 25, 2012 by Nancy Atkinson

What Really Happened on Apollo 13?

Apollo 13 crew reflects on the mission from David Meerman Scott on Vimeo.

Hear the story of what really happened on Apollo 13 from two of the astronauts who were on board, Jim Lovell and Fred Haise. Lovell provides great detail on the history of the oxygen tank and why it exploded, and both Lovell and Haise have some great stories to share about the flight, movie inaccuracies and more. Thanks to David Meerman Scott from Apollo Artifacts who took this video at the Kennedy Space Center at the Astronaut Scholarship Foundation event on November 6, 2009.

Also on Apollo Artifacts, check out a video of short speech by Neil Armstrong who gave a tribute to the Apollo 12 crew at the flight’s 40th anniversary gala on November 7, 2009.

November 8, 2009December 24, 2015 by Nancy Atkinson

Surviving 2012: Ian O’Neill on Discovery Channel Sunday Night

Our very own resident expert on 2012, Dr. Ian O’Neill will be on a special Discovery Channel show, premiering Sunday evening. I just saw a promo piece on the Discovery Channel, and it looks really great. On TV, they called it Surviving 2012, however online it is titled Apocalypse 2012. On his blog, Astroengine, Ian says that science is the focus on this show, (unlike the idiotic Nostradamus nonsense on another channel). As you probably know, Ian is now the producer over at Discovery Space, (and doing a bang-up job!) but he still posts on UT now and then. His series of articles on 2012 are outstanding, and are some of our most popular articles, so I can’t wait to see him debunk the nonsense on television. The Discovery Channel in my area (US Central Time) says 8 pm, but check your own local listing. And if you miss it Sunday night, check for repeat showings later in the week. Go Ian!

November 7, 2009December 24, 2015 by Nancy Atkinson

One Strange Mars Rock

Opportunity has come upon another big rock on Mars. But what is it? Another meteorite? A big clump of ejecta from an old impact? There’s lots of other debris scattered around this area as well. The rock has been named “Marquette Island,” staying with the island theme for the other meteorites Oppy has come across, and the rover may take the “opportunity” to get closer to this rock and check it out, given the sand dunes surrounding it don’t provide too much of an obstacle. So maybe next week we’ll find out what it is. But in the meantime, enjoy these color and 3-D images (see more below) of the rock via Stu Atkinson from Unmannedspaceflight.com. Check out more great looks at Marquette Island at Stu’s blog about Oppy’s travels, Road to Endeavour.

Oh, and rumor has it that the extrication process may have begun to free the Spirit rover. Latest images show she has moved every so slightly. More as it becomes available….

Marquette Island, from a distance. Credit: NASA/JPL, color by Stu Atkinson

Marquette Island in 3-D. Credit: NASA/JPL, 3-D by Stu Atkinson

November 6, 2009December 24, 2015 by Nancy Atkinson

Early Galaxy Pinpoints Reionization Era

This is a composite of false color images of the galaxies found at the early epoch around 800 million years after the Big Bang. The upper left panel presents the galaxy confirmed in the 787 million year old universe. These galaxies are in the Subaru Deep Field. Credit: M. Ouchi et al.

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Astronomers looking to pinpoint when the reionozation of the Universe took place have found some of the earliest galaxies about 800 million years after the Big Bang. 22 early galaxies were found using a method that looks for far-away redshifting sources that disappear or “drop-out” at a specific wavelength. The age of one galaxy was confirmed by a characteristic neutral hydrogen signature at 787 million years after the Big Bang. The finding is the first age-confirmation of a so-called dropout galaxy at that distant time and pinpoints when the reionization epoch likely began.

The reionization period is about the farthest back in time that astronomers can observe. The Big Bang, 13.7 billion years ago, created a hot, murky universe. Some 400,000 years later, temperatures cooled, electrons and protons joined to form neutral hydrogen, and the murk cleared. Some time before 1 billion years after the Big Bang, neutral hydrogen began to form stars in the first galaxies, which radiated energy and changed the hydrogen back to being ionized. Although not the thick plasma soup of the earlier period just after the Big Bang, this star formation started the reionization epoch.

Astronomers know that this era ended about 1 billion years after the Big Bang, but when it began has eluded them.

We look for ‘dropout’ galaxies,” said Masami Ouchi, who led a US and Japanese team of astronomers looking back at the reionization epoch. “We use progressively redder filters that reveal increasing wavelengths of light and watch which galaxies disappear from or ‘dropout’ of images made using those filters. Older, more distant galaxies ‘dropout’ of progressively redder filters and the specific wavelengths can tell us the galaxies’ distance and age. What makes this study different is that we surveyed an area that is over 100 times larger than previous ones and, as a result, had a larger sample of early galaxies (22) than past surveys. Plus, we were able to confirm one galaxy’s age,” he continued. “Since all the galaxies were found using the same dropout technique, they are likely to be the same age.”

Ouchi’s team was able to conduct such a large survey because they used a custom-made, super-red filter and other unique technological advancements in red sensitivity on the wide-field camera of the 8.3-meter Subaru Telescope. They made their observations from 2006 to 2009 in the Subaru Deep Field and Great Observatories Origins Deep Survey North field. They then compared their observations with data gathered in other studies.

Astronomers have wondered whether the universe underwent reionization instantaneously or gradually over time, but more importantly, they have tried to isolate when the universe began reionization. Galaxy density and brightness measurements are key to calculating star-formation rates, which tell a lot about what happened when. The astronomers looked at star-formation rates and the rate at which hydrogen was ionized.

Using data from their study and others, they determined that the star-formation rates were dramatically lower from 800 million years to about one billion years after the Big Bang, then thereafter. Accordingly, they calculated that the rate of ionization would be very slow during this early time, because of this low star-formation rate.

“We were really surprised that the rate of ionization seems so low, which would constitute a contradiction with the claim of NASA’s WMAP satellite. It concluded that reionization started no later than 600 million years after the Big Bang,” remarked Ouchi. “We think this riddle might be explained by more efficient ionizing photon production rates in early galaxies. The formation of massive stars may have been much more vigorous then than in today’s galaxies. Fewer, massive stars produce more ionizing photons than many smaller stars,” he explained.

The research will be published in a December issue of the Astrophysical Journal.

Source: EurekAlert

November 6, 2009December 24, 2015 by Nancy Atkinson

Space Junk May Force Crew from ISS

Update #2, 5:30 pm: NASA has now said that after further analysis, the space debris they have been tracking no longer poses any concern or threat to the ISS. Everyone can rest easy tonight! The piece of debris was only 5 cm long, and will not pass within the “pizza box” zone around the station (0.75 x 25 x 25 kilometers) that calls for an alert.

A hard-to-track piece of space junk may come within a half a kilometer of the International Space Station later today, and NASA managers are considering asking the crew to board the docked Soyuz capsules as a precaution. The time of closest approach is at 10:48 p.m. EST, and the object was detected too late for the station to do an evasive maneuver. Depending on the outcome of additional tracking data analysis, the crew may be awakened later and directed to go into the Soyuz vehicles around 10:30 pm or given the option to sleep in Soyuz tonight. NASA says they don’t believe the crew is at risk, but precautions are prudent in dealing with space debris.

The crew was told about the debris, which ground stations have not been able to track consistently, said NASA spokesman Kyle Herring. Trajectory experts are continuing to verify information about the debris. “All this is a precaution, and we do not believe the crew is in any danger at this time or at the time of closest approach, but are making preparations in the unlikely event the approach would be closer than expected,” Herring said.

UPDATE: 2:30pm: As of now, NASA is planning for the crew to close all the hatches on the station and enter the Soyuz. “We have data that indicates we might be heading to a conjunction, however we do not have enough data to have any confidence in the outcomes we’re predicting at this point,” Capcom Ricky Arnold told the crew from mission control. “We’re hoping we’re going to be a lot smarter at 2200 (GMT), but right now we have to plan for an indication that we will have a conjunction.”

NASA will make a final decision on what course of action they will take at about 5 p.m.

Sources: NASA TV, Twitter