Universe Today

April 11, 2014December 23, 2015 by Elizabeth Howell

Twin Peeks: Astronaut Brothers To Go Under Microscope During One-Year Mission

NASA astronaut Scott Kelly plays with fresh fruit in the Unity node of the International Space Station. This 2010 picture was taken during Expedition 25. Credit: NASA

Identical twin astronauts, one headed to space for a year and the other happily at home. Imagine just how excited health researchers are by the prospect of this situation which yes, is happening for real. Scott Kelly is preparing to blast off on a lengthy mission to the International Space Station in 2015 while his retired twin, Mark, will serve as a control.

The 50-year-old men will do a suite of experiments before, during and after the mission to see how much (if at all) Scott’s body changes from his brother in the long term. This ranges from examining their DNA, to their vision, and even changes in the gut.

“These will not be 10 individual studies,” stated Craig Kundrot of NASA’s human research program at the Johnson Space Center. “The real power comes in combining them to form an integrated picture of all levels from biomolecular to psychological. We’ll be studying the entire astronaut.”

One experiment will examine telomeres, which NASA says are “molecular caps” that sit on the ends of human DNA. As the theory goes, these telomeres are affected in space by cosmic rays (high-energy particles originating from outside the solar system) — which could speed up the aging process. If Scott’s telomeres change after the mission, this could help determine if space is linked to rapid aging.

Another experiment asks how the immune system alters. “We already know that the human immune system changes in space. It’s not as strong as it is on the ground,” said Kundrot. “In one of the experiments, Mark and Scott will be given identical flu vaccines, and we will study how their immune systems react.”

Then there are experiments looking at gut bacteria that help digestion, seeking out how human vision changes, and even a phenomenon known as “space fog” — how some astronauts find themselves losing alertness in orbit.

Although the twins have inherent fascination for researchers and sociologists, the Kellys themselves have emphasized that to them, having an identical counterpart is something that always was.

NASA astronaut Mark Kelly peers out a window during the penultimate shuttle mission, STS-134, in 2011. Around his neck is the ring of his wife, Gabrielle Giffords, who was recovering from a gunshot head wound during the mission. Credit: NASA

“We didn’t know anything differently and, you know, he’s not my clone,” Scott said in a joint 2010 NASA interview with Mark.

“You know, a lot of times people would ask, ‘So what’s it like to be a twin?’ and … the response I would usually give is, ‘Well, what’s it like not to be a twin?’ I mean, it’s just, it is,” Mark added, to which Scott responded, “It’s more like … he’s my brother but we just happen to have the same birthday, to me.”

Scott will leave Earth with Russian cosmonaut Mikhail Kornienko in 2015 for the first one-year mission in space since a handful of lengthy stays on the former Russian space station, Mir, in the 1990s. Scott will serve as Expedition 43/44 flight engineer and have the distinction of commanding two space station missions, Expedition 45 and 46. (He also commanded Expedition 26 in 2010.)

Source: NASA

April 11, 2014December 23, 2015 by Elizabeth Howell

After The Flood: Ancient Waters Carved These Martian Channels

A December 2013 image of Osuga Valles taken by the European Space Agency's Mars Express spacecraft, highlighted by the agency in April 2014. Credit: ESA/DLR/FU Berlin

This picture is an example of why Martian scientists like to get their groove on. This late 2013 snapshot of Osuga Valles — a part of the vast Valles Marineris gorge that cuts across the Red Planet — shows the leftovers of an ancient flood. The European Space Agency highlighted the area in a release this week.

“Catastrophic flooding is thought to have created the heavily eroded Osuga Valles and the features within it. Streamlines around the islands in the valley indicate that the direction of flow was towards the northeast … and sets of parallel, narrow grooves on the floor of the channel suggest that the water was fast flowing,” the European Space Agency stated.

“Differences in elevation within the feature, along with the presence and cross-cutting relationships of channels carved onto the islands, suggest that Osuga Valles experienced several episodes of flooding.”

Things get even more interesting when you look a bit closer up, as you can see below.

A close-up view of Osuga Valles created from data acquired with the Mars Express' High Resolution Stereo Camera. Water flowed towards the top of this image. Credit: ESA/DLR/FU Berlin — A close-up view of Osuga Valles created from data acquired with the Mars Express’ High Resolution Stereo Camera. Water flowed towards the top of this image. Credit: ESA/DLR/FU Berlin

“The grooved nature of the valley floor suggests the water was fast flowing, carving out the features as it flooded the region,” ESA added. “The elevated ‘island’ blocks are also carved with small channels, recording the history of previous flood episodes.”

You can read more about Mars Express’ 10 years of exploration at this ESA website. We’ve also highlighted the top 10 discoveries in this past Universe Today story.

Source: European Space Agency

April 11, 2014December 23, 2015 by Elizabeth Howell

Supernova Sweeps Away Rubbish In New Composite Image

The supernova remnant G352.7-0.1 in a composite image with X-rays from the Chandra X-Ray Telescope (blue), radio waves from the Very Large Array (pink), infrared information from the Spitzer Space Telescope (orange) and optical data from the Digital Sky Survey (white). Credit: X-ray: NASA/CXC/Morehead State Univ/T.Pannuti et al.; Optical: DSS; Infrared: NASA/JPL-Caltech; Radio: NRAO/VLA/Argentinian Institute of Radioastronomy/G.Dubner

Shining 24,000 light-years from Earth is an expanding leftover of a supernova that is doing a great cleanup job in its neighborhood. As this new composite image from NASA reveals, G352.7-0.1 (G352 for short) is more efficient than expected, picking up debris equivalent to about 45 times the mass of the Sun.

“A recent study suggests that, surprisingly, the X-ray emission in G352 is dominated by the hotter (about 30 million degrees Celsius) debris from the explosion, rather than cooler (about 2 million degrees) emission from surrounding material that has been swept up by the expanding shock wave,” the Chandra X-Ray Observatory’s website stated.

“This is curious because astronomers estimate that G352 exploded about 2,200 years ago, and supernova remnants of this age usually produce X-rays that are dominated by swept-up material. Scientists are still trying to come up with an explanation for this behavior.”

More information about G352 is available in the Astrophysical Journal and also in preprint version on Arxiv.

Source: Chandra X-Ray Telescope

April 10, 2014April 26, 2016 by Ken Kremer

Super Secret Spy Satellite Soars Spectacularly to Space aboard Atlas V booster from Cape Canaveral – Launch Gallery

Blastoff of the Atlas V rocket with the super secret NROL-67 intelligence gathering payload on April 10, 2014 from Cape Canaveral Air Force Station, Fla. Credit: Alan Walters/AmericaSpace
Launch gallery expanded and updated – with timelapse ![/caption]

A super secret US spy satellite soared spectacularly to space this afternoon from Cape Canaveral atop a very powerful version of the Atlas V rocket on a classified flight for the National Reconnaissance Office.

The United Launch Alliance (ULA) Atlas V carrying the NROL-67 intelligence gathering satellite on a US national security mission for the NRO lifted off from Space Launch Complex-41 ignited its engines precisely on the targeted time on April 10 at 1:45 p.m. EDT into brilliant blue Florida skies on Cape Canaveral Air Force Station.

This mighty version of the 191 ft (58 m) tall Atlas V whose thrust was augmented with four strap on solid rocket motors has only been used once before – to loft NASA’s Curiosity rover to the Red Planet back in November 2011.

Atlas V NROL-67 launch photographed by iPhone from Cocoa Beach on April 10, 2014 while swimming. Credit: Nicole Solomon — Atlas V NROL-67 launch photographed by iPhone from Cocoa Beach on April 10, 2014 while swimming with the Florida fish. Credit: Nicole Solomon

Today’s Atlas V launch, as well as another for SpaceX/NASA, was postponed over two weeks ago from March 25 & 30 amidst final launch preparations when an electrical short completely knocked out use of the US Air Force’s crucial tracking radar that is mandatory to insure public safety for all launches on the Eastern Range.

Atlas V/NROL-67 spy satellite soars off Launch Complex 41 at Cape Canaveral on April 10, 2014. Credit: Jeff Seibert/WiredforSpace — Atlas V/NROL-67 spy satellite soars off Launch Complex 41 at Cape Canaveral on April 10, 2014. Credit: Jeff Seibert/Wired4space.com

Nothing is publicly known about the NROL surveillance satellite, its capabilities, orbit or mission or goals.

Due to the covert nature of this mission, the flight entered the now standard total news blackout and the TV transmission ceased barely five minutes after liftoff.

The successful blastoff follows closely on the heels of another Atlas V launch just seven days ago.

On April 3, ULA launched a less powerful version of the Atlas V carrying an Air Force weather satellite from Vandenberg Air Force Base, Calif.

Clear of the catenary lightning wires the Atlas 5-541 booster with its NROL-67 payload roar to orbit on April 10, 2014 from Cape Canaveral, FL. Credit: nasatech.net

“We are honored to deliver this national security asset to orbit together with our customers the NRO Office of Space Launch and the Air Force,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs.

“Successfully launching two missions from two different coasts in just seven days is a testament to the team’s one-launch-at-a-time focus and ULA’s commitment to mission success and schedule reliability.”

Today’s liftoff involved use of the Atlas V in the 541 configuration. The NROL-67 payload was housed inside a 5-meter diameter payload fairing. And a total of four US built Aerojet Rocketdyne solid rocket motors were mounted on the first stage of the booster.

The Centaur upper stage which boosted NROL-67 to Earth orbit was powered by a single Aerojet Rocketdyne RL10A engine.

The Atlas V first stage was also powered by the dual nozzle RD AMROSS RD-180 engine manufactured in Russia.

Use of the Russian designed and built RD AMROSS RD-180 engine potentially puts Atlas V launches and US National Security launches at risk, if the crisis in Ukraine and Crimea spins out of control as I have reported previously.

“ULA maintains a two year stockpile of the RD-180 engines at all times,” ULA Jessica Rye spokesperson told me recently at Cape Canaveral Air Force Station.

The next ULA launch from the Cape is scheduled for May 15 when a Delta IV rocket will loft the GPS IIF-6 mission for the United States Air Force from Space Launch Complex-37.

Rising quickly from Pad 41 on its RD-180 and 4 SRBs, the Atlas 5-541 vehicle begins its mission to geosync orbit. Credit: nasatech.net

A SpaceX Falcon 9 is slated to launch on Monday, April 14 at 4:58 p.m. EDT.

The Falcon 9 is lofting a SpaceX Dragon cargo ship and delivering some 5000 pounds of science experiments and supplies for the six man space station crew – under a resupply contract with NASA.

Also packed aboard the Dragon are a pair of legs for NASA’s experimental Robonaut 2 crew member.

Stay tuned here for Ken’s continuing Atlas V NROL 67, SpaceX, Orbital Sciences, commercial space, Orion, Chang’e-3, LADEE, Mars rover, MAVEN, MOM and more planetary and human spaceflight news.

Learn more at Ken’s upcoming presentations at the NEAF astro/space convention, NY on April 12/13.

Ken Kremer

Startled Florida space coast sunbathers see sudden blastoff of Atlas V/NROl-67 from Cocoa Beach on April 10, 2014. Credit: Nicolle Solomon by iPhone — Startled Florida space coast sunbathers see sudden blastoff of Atlas V/NROl-67 from Cocoa Beach on April 10, 2014. Credit: Nicole Solomon by iPhone

Timelapse of Atlas V/NROL-67 blastoff on April 10, 2014. Credit: Chuck Higgins

April 10, 2014 blastoff of Atlas V rocket with super secret NROL-67 intelligence gathering payload from Cape Canaveral Air Force Station, Fla. Credit: Ken Kremer/kenkremer.com

Atlas V rocket and Super Secret NROL-67 intelligence gathering payload following rollout to Space Launch Complex 41 at Cape Canaveral Air Force Station, FL, on March 24, 2014. Credit: Ken Kremer - kenkremer.com — Atlas V rocket and Super Secret NROL-67 intelligence gathering payload following rollout to Space Launch Complex 41 at Cape Canaveral Air Force Station, FL. The Atlas V launched on April 10, 2014. Credit: Ken Kremer – kenkremer.com

April 10, 2014December 23, 2015 by Jason Major

JPL Tests Big with a Supersonic Parachute for Mars

No rocket sleds were harmed in the making of this video. (NASA/JPL)

“You wanna go to Mars, you wanna go big? Then you gotta test big here,” says mechanical engineer Michael Meacham, and testing big is exactly what he and other engineers at NASA’s Jet Propulsion Laboratory have done to develop a new supersonic parachute for future Mars landings.

The process of putting things onto Mars has traditionally used the same couple of tried-and-true methods: inflatable, shock-absorbing bouncers and large parachutes combined with retro-rockets (most recently seen in the famous “Seven Minutes of Terror” Curiosity landing in August 2012.) But both methods are limited in how large and massive of an object can safely be placed on the Martian surface. For even larger-scale future missions, new technology will have to be developed to make successful landings possible.

Enter the LDSD, or Low-Density Supersonic Decelerator, an enormous parachute — similar to the one used by Curiosity except bigger — that can slow the descent of even more massive payloads through the thin Martian atmosphere.

Of course, part of the development process is testing. And in order to run such a large chute through the same sorts of rigors it would experience during an actual Mars landing, JPL engineers had to step outside of the wind tunnel and devise another method.

The one they came up with involves a rocket sled, a Night Hawk helicopter, a 100-lb steel bullet, a kilometer-long cable (and lots and lots of math.) It’s an experiment worthy of “Mythbusters”… watch the video above to see how it turned out.

“When we land spacecraft on Mars, we’re going extremely fast… we have got to slow down. So we use a parachute. And we use a really BIG parachute.”
– Michael Meacham, Mechanical Engineer at JPL

How CERN’s Discovery of Exotic Particles May Affect Astrophysics

The difference between a neutron star and a quark star (Chandra)

You may have heard that CERN announced the discovery (confirmation, actually. See addendum below.) of a strange particle known as Z(4430). A paper summarizing the results has been published on the physics arxiv, which is a repository for preprint (not yet peer reviewed) physics papers. The new particle is about 4 times more massive than a proton, has a negative charge, and appears to be a theoretical particle known as a tetraquark. The results are still young, but if this discovery holds up it could have implications for our understanding of neutron stars.

A periodic table of elementary particles. Credit: Wikipedia — A periodic table of elementary particles.
Credit: Wikipedia

The building blocks of matter are made of leptons (such as the electron and neutrinos) and quarks (which make up protons, neutrons, and other particles). Quarks are very different from other particles in that they have an electric charge that is 1/3 or 2/3 that of the electron and proton. They also possess a different kind of “charge” known as color. Just as electric charges interact through an electromagnetic force, color charges interact through the strong nuclear force. It is the color charge of quarks that works to hold the nuclei of atoms together. Color charge is much more complex than electric charge. With electric charge there is simply positive (+) and its opposite, negative (-). With color, there are three types (red, green, and blue) and their opposites (anti-red, anti-green, and anti-blue).

Because of the way the strong force works, we can never observe a free quark. The strong force requires that quarks always group together to form a particle that is color neutral. For example, a proton consists of three quarks (two up and one down), where each quark is a different color. With visible light, adding red, green and blue light gives you white light, which is colorless. In the same way, combining a red, green and blue quark gives you a particle which is color neutral. This similarity to the color properties of light is why quark charge is named after colors.

Combining a quark of each color into groups of three is one way to create a color neutral particle, and these are known as baryons. Protons and neutrons are the most common baryons. Another way to combine quarks is to pair a quark of a particular color with a quark of its anti-color. For example, a green quark and an anti-green quark could combine to form a color neutral particle. These two-quark particles are known as mesons, and were first discovered in 1947. For example, the positively charged pion consists of an up quark and an antiparticle down quark.

Under the rules of the strong force, there are other ways quarks could combine to form a neutral particle. One of these, the tetraquark, combines four quarks, where two particles have a particular color and the other two have the corresponding anti-colors. Others, such as the pentaquark (3 colors + a color anti-color pair) and the hexaquark (3 colors + 3 anti-colors) have been proposed. But so far all of these have been hypothetical. While such particles would be color neutral, it is also possible that they aren’t stable and would simply decay into baryons and mesons.

There has been some experimental hints of tetraquarks, but this latest result is the strongest evidence of 4 quarks forming a color neutral particle. This means that quarks can combine in much more complex ways than we originally expected, and this has implications for the internal structure of neutron stars.

Very simply, the traditional model of a neutron star is that it is made of neutrons. Neutrons consist of three quarks (two down and one up), but it is generally thought that particle interactions within a neutron star are interactions between neutrons. With the existence of tetraquarks, it is possible for neutrons within the core to interact strongly enough to create tetraquarks. This could even lead to the production of pentaquarks and hexaquarks, or even that quarks could interact individually without being bound into color neutral particles. This would produce a hypothetical object known as a quark star.

This is all hypothetical at this point, but verified evidence of tetraquarks will force astrophysicists to reexamine some the assumptions we have about the interiors of neutron stars.

Addendum: It has been pointed out that CERN’s results are not an original discovery, but rather a confirmation of earlier results by the Belle Collaboration. The Belle results can be found in a 2008 paper in Physical Review Letters, as well as a 2013 paper in Physical Review D. So credit where credit is due.

April 10, 2014December 23, 2015 by Elizabeth Howell

Asteroid That Dwarfed Dinosaur-Killer Punched Earth 3 Billion Years Ago, Study Says

A graphic comparing the asteroid that killed the dinosaurs, with an asteroid newly believed to have struck the Earth 3.26 billion years ago. Below the asteroids is a graphic showing how big the craters would have been. Credit: American Geophysical Union

Early in Earth’s history, a killer asteroid smashed a hole in our planet about 300 miles (500 kilometers) wide, which is greater than the driving distance between Washington and New York City, a new study says. The space rock set off a cycle of destruction that sounds like your worst nightmares.

That one reported collision 3.26 billion years ago made the Earth tremble, created earthquakes and set off tsunamis that were thousands of meters deep, according to a new research team. The size of this estimated destructor? About 37 kilometers (23 miles) wide, or about three times as wide as the asteroid that killed the dinosaurs 65 million years ago.

“We knew it was big, but we didn’t know how big,” stated co-author Donald Lowe, a geologist at Stanford University and a co-author of the study, of the asteroid.

Evidence of the huge impact — the first one mapped from so long ago — comes from an examination of the Barberton Greenstone Belt in South Africa, which shows rocks and “crustal fractures” that are consistent with the idea of a giant impact, the scientists said. (The asteroid struck the Earth thousands of miles away, but where isn’t known.)

An satellite view of Barberton greenstone around the town of Barberton, South Africa. Credit: NASA Earth Observatory/Landsat/U.S. Geological Survey/Jesse Allen

If confirmed, the asteroid could have been one of many that smacked Earth during what is known as the Late Heavy Bombardment period, which pummeled the solar system with debris between 3 billion and 4 billion years ago.

This one event could even have changed the way the Earth formed, the scientists added. For example, it could have been broken up our planet’s crust and tectonics, creating the plate tectonics we are familiar with today.

You can read more about the research in the journal Geochemistry, Geophysics, Geosystems. It was led by Norman Sleep, a geophysicist at Stanford University.

Source: American Geophysical Union

April 10, 2014March 8, 2017 by Fraser Cain

Can Tatooine Be Real?

We’re familiar with the sky on Tatooine with its twin suns. But could a planet actually orbit two stars at the same time? Could you have a planet in a multiple star system with 4, 6 or more suns?

Hey kids, you remember Star Wars right? Tatooine ring any bells? Lots of sand Tusken raiders walking single file. Banthas sweating all over the place like some crazy mammoth-goat breeding experiment gone horribly awry?
Tatooine was an arid desert planet, it had 2 suns and 3 moons. It’s not the only fictional planet to orbit multiple suns. In Nightfall by Isaac Asimov, planet Lagash had 6 suns. Could something like this be possible?

Interestingly, most stars in the Milky Way are in multiple star systems. You can easily have double, triple, or quadruple systems. There are even star clusters with hundreds or even thousands of stars. Just imagine the crazy chaotic gravitational interactions in a multiple star system.

So, could they have planets? Yes. There are circumbinary systems, where stars orbit each other their planets orbit outside, circling them both. Since the stars orbit one another so closely, it’s the gravitational equivalent of a single star. From an orbiting planet, the stars would always appear together in the sky.

To date, we have discovered 17 of these systems. Then there are wide binary systems, which are far more dangerous for planets. Here the planets orbit one main star, and there’s another star which maintains a distant orbit much further out. You don’t want to live there. The gravitational interactions are chaotic and lead to mayhem. In simulations, planets which aren’t tightly orbiting a star are ejected out of the system, or crashed into other planets or stars.

Artist's impression of the Cygnus-X1 binary. Credit: NASA / Honeywell Max-Q Digital Group / Dana Berry — Artist’s impression of the Cygnus-X1 binary. Credit: NASA / Honeywell Max-Q Digital Group / Dana Berry

We might already be detecting highly elliptical orbits from disrupted planets just like these. A triple star system was recently discovered in the constellation Cygnus: HD 188753. Here, a pair of stars are tightly bound, and these are in a wide binary arrangement with a sun-mass star. A planet closely orbits the primary star, but all other planets were likely ejected.

In the year 2012, a planet was found around Alpha Centauri B, and PH1 was the first quadruple star system to be discovered to have a planet. Kepler 47 is a multi-star, multi-planet system. Two stars orbit one another every 7.45 days. Here, the gas giant Kepler 47c orbits the stars every 303 days and is even located in the habitable zone. This sounds like perfect concept art for a Vin Diesel film, or artwork airbrushed on the side of a van.

Kepler-16b is but one example of an uncanny world. It orbits two suns. Credit: Discovery

Finally, In 2011, the Kepler-16 system was found to have a circumbinary planet in the habitable zone. So, two stars, closely orbiting each other and a Saturn-mass, Kepler 16b orbiting the two. Astronomers informally called this a real Tatooine.

What do you think? Would you want to live on a desert world like Tatooine or Arrakis? Tell us your thoughts in the comments below.

April 10, 2014December 23, 2015 by David Dickinson

Two Observing Challenges: Catch Venus Passing Neptune And Occulting a Bright Star

The Milky Way, The Large and Small Magellanic Clouds, Zodiacal Light, and Venus as seen from the Karoo Desert in South Africa early this month. Credit: Cory Schmitz.

Have you been following the planet Venus this season? 2014 sees the brightest planet in our Earthly skies spend a majority of its time in the dawn. Shining at magnitude -3.8, it’s hard to miss in the morning twilight. But dazzling Venus is visiting two unique celestial objects over the next week, and both present unique observing challenges for the seasoned observer.

First up is an interesting close conjunction of the planets Venus and Neptune on the morning of Saturday, April 12^th. Closest conjunction occurs at 3:00 Universal Time (UT) April 12th favoring Eastern Europe, the Middle East and eastern Africa, when the two worlds appear to be just 40 arc minutes apart, a little over – by about 10’ – the apparent size of a full Moon. Shining at magnitude +7.8 and 30,000 times fainter than Venus, you’ll need a telescope to tease out Neptune from the pre-dawn sky. Both objects will, however, easily fit in a one degree field of view, in addition to a scattering of other stars.

Looking to the east the morning of April 12th from the U.S. East Coast near latitude 30 degrees north. Nearby stars are annotated in red by magnitude with decimals omitted. Created using Stellarium, click to enlarge.

At low power, Venus will display a 59% illuminated gibbous phase 20” across on the morning of the 12^th, while Neptune will show a tiny disk barely 2” across. Still, this represents the first chance for viewers to recover Neptune since solar conjunction behind the Sun on February 23^rd, 2014, using dazzling Venus as a guide.

Both sit 45 degrees west of the Sun and currently rise around 3 to 4 AM local dependent on latitude.

This is one of the closest planet-planet conjunctions for 2014. The closest is Venus and Jupiter at just 0.2 degrees apart on August 18^th. This will represent the brightest planet versus planet conjunction for the year, and is sure to illicit multiple “what’s those two bright stars in the sky?” queries from morning commuters… hopefully, such sightings won’t result in any border skirmishes worldwide.

Now, for the mandatory Wow factor. On the date of conjunction, Earth-sized Venus is 0.84 Astronomical Units (A.U.s) or over 130 million kilometres distant. Ice giant Neptune, however, is 30.7 AUs or 36 times as distant, and only appears tiny though it’s almost four times larger in diameter. Sunlight reflected from Venus takes 7 minutes to reach Earth, but over four hours to arrive from Neptune. We’ve visited Venus lots, and the Russians have even landed there and returned images from its smoldering surface, but we’ve only visited Neptune once, during a brief flyby of Voyager 2 in 1989.

From Neptune looking back on April 12th, Earth and Venus would appear less than 1 arc minute apart…. though they’d also be just over one degree from the Sun!

The "shadow path" of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0. — The “shadow path” of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0.

But an even more bizarre event happens a few days later on April 16^th, though only a small region of the world in the South Pacific may bare witness to it.

Next Wednesday from 17:59 to 18:13 UT Venus occults the +3.7 magnitude star HIP 112961 also known as Lambda Aquarii on the morning of April 16^th 2014.

Venus will be a 61% illuminated gibbous phase 19” in diameter. Unfortunately, although North America is rotated towards the event, it’s also in the middle of the day.

The best prospects to observe the occultation are from New Zealand and western Pacific at dawn. The star will disappear behind the bright limb of Venus in dawn twilight before emerging on its dark limb 5 minutes later as seen from New Zealand.

The path of Lambda Aquarii behind Venus as seen from New Zealand the morning of the 16th. Created in Starry Night.

Note: New Zealand switched back to standard time on April 6^th – it’s currently Fall down under – and local sunrise occurs around ~7:40 AM.

Lambda Aquarii is a 3.6 solar mass star located 390 light years distant. As far as we know, it’s a solitary star, though there’s always a chance that a companion could make itself known as it emerges on the dark limb of Venus. Such an observation will, however, be extremely difficult, as Venus is still over 700 times brighter than the star!

North Americans get to see the pair only 20’ apart on the morning of the 12^th.

And further occultation adventures await Venus in the 21^st century. On October 1^st, 2044 it will occult Regulus… and on November 22^nd, 2065 it will actually occult Jupiter!

Such pairings give us a chance to image Venus with a “pseudo-moon.” Early telescopic observers made numerous sightings of a supposed Moon of Venus, and the hypothetical object even merited the name Neith for a brief time. Such sightings were most likely spurious internal reflections due to poor optics or nearby stars, but its fun to wonder what those observers of old might’ve seen.

… and speaking of moons, don’t miss a chance to see Venus near the daytime Moon April 25^th. Follow us as @Astroguyz on Twitter as we give shout outs to these and other strange pairings daily!

April 10, 2014December 23, 2015 by Elizabeth Howell

European Satellite Dodged Space Debris Hours After Reaching Orbit

Artist's conception of Sentinel-1, an environment-monitoring satellite from the European Space Agency. Credit: ESA/ATG medialab

Yesterday, the European Space Agency disclosed a serious problem early in the Sentinel-1A mission, which lifted off April 3 on a mission to observe the Earth. The spacecraft — which reportedly cost 280 million Euros ($384 million) to launch — came close to a collision in orbit.

“At the end of the first day after the launch (4 April): all deployments have been executed during the night and completed early in the morning at the beginning of the first ‘day shift’,” read a blog post from the Sentinel-1A team on the European Space Agency’s website.

“As the first day shift nears its end, a serious alert is received: there is a danger of a collision with a NASA satellite called ACRIMSAT, which has run out of fuel and can no longer be maneuvered. Not much information at the beginning, we are waiting for more information, but a collision avoidance maneuver may be needed. ‘Are you kidding? A collision avoidance maneuver during LEOP [launch and early orbit phase]? This has never been done before, this has not been simulated!’ ”

Worse, as controllers looked at the data they realized there was not one, but two possible points of collision. Cue the inevitable Gravity reference, and then a solution: to essentially move the satellite out of the way. The maneuver took about 39 seconds, and safely skirted Sentinel-1A out of danger.

You can read more about the situation in the blog post. ESA’s main Twitter feed and the ESA Operations Twitter feed also first reported the near-collision yesterday, nearly a week after it occurred. It should also be noted that the Europeans (among many other space agencies) are looking at ways to reduce space debris.