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February 5, 2016March 18, 2016 by Evan Gough

Jupiter Not the Planetary Protector We Thought it Was?

Jupiter takes a beating from Comet Shoemaker-Levy 9. Credit: NASA/Hubble Space Telescope team.

I’ve always liked the idea that Jupiter has acted like a protector to its little brother, Earth. That it has used its massive gravitational pull to divert asteroids and comets from a collision course with Earth. Maybe Jupiter even felt bad when one got through, and doomed the dinosaurs to extinction. But a new study has cast this idea into doubt.

The idea of Jupiter as a protector has been around for a while. The images of comet Shoemaker-Levy 9 breaking apart and crashing into Jupiter in 1994 reinforced the idea. But according to Kevin Grazier, at the Jet Propulstion Laboratory (JPL), rather than acting solely as a shield, re-directing comets and other objects away from the inner solar system, Jupiter may have actually directed planetesimals into the inner solar system.

Illustration of a rocky planet being bombarded by comets. (Image credit: NASA/JPL-Caltech)

In the early days of the Solar System, there was much more debris around than there is now. The early days would have been a race between planetesimals to gather enough mass to form the planets we see today. After planets were formed, there would still have been plenty of planetesimals left. This new study shows that, rather than clearing the inner solar system from all this debris that could collide with Earth, Jupiter nudged many of these planetesimals towards Earth, helping to create Earth as we know it.

As reported in January 2016 in Astrobiology, Glazier created a simulator of the solar system, and ran 30,000 particles through this simulation. All of the particles began in “non life-threatening” trajectories, but a significant number of them ended the simulation in orbits that crossed the orbit of the Earth.

So not only did Jupiter—and Saturn—re-direct material into the inner Solar System, but the simulation also showed that Jupiter slowed that material to a speed which allowed it to contribute mass to Earth.

But these planetesimals would have contributed more than just mass to Earth. They would have carried volatiles with them. Volatiles are chemical elements and molecules with low boiling points. They are associated with the atmosphere and the crust. These volatiles, which include nitrogen, hydrogen, carbon dioxide, and others, make up a large portion of the Earth’s crust. Without them, Earth would be a very different place. It may never have developed the atmosphere that has allowed life to flourish.

It’s clear that Jupiter has contributed to the evolution of Earth and the Solar System as we know it. As the largest planet by far, its influence is undeniable. As a result of this study, we better understand the dual-role Jupiter has played. While it no doubt has played the role of protector, by changing the direction of some objects on a collision course with Earth, Jupiter’s presence has also been responsible for slowing and diverting planetesimals—and their life-friendly volatiles—directly into Earth.

February 5, 2016March 18, 2016 by Evan Gough

Earth From Afar Would Look Only 82% Right For Life

From Lunar orbit, Earth is obviously habitable. But from a distant point in the galaxy, not so much. Image: NASA/LRO.

Right now, we’re staring hard at a small section of the sky, to see if we can detect any planets that may be habitable. The Kepler Spacecraft is focused on a tiny patch of sky in our Milky Way galaxy, hoping to detect planets as they transit in front of their stars. But if alien astronomers are doing the same, and detect Earth transiting in front of the Sun, how habitable would Earth appear?

You might think, because, well, here we are, that the Earth would look 100% habitable from a distant location. But that’s not the case. According to a paper from Rory Barnes and his colleagues at the University of Washington-based Virtual Planetary Laboratory, from a distant point in the galaxy, the probability of Earth being habitable might be only 82%.

Illustration of the Kepler spacecraft.(NASA/Kepler mission/Wendy Stenzel)

Barnes and his team came up with the 82% number when they worked to create a “habitability index for transiting planets,” that seeks to rank the habitability of planets based on factors like the distance from its star, the size of the planet, the nature of the star, and the behaviour of other planets in the system.

The search for habitable exo-planets is dominated by the idea of the circumstellar habitable zone—or Goldilocks Zone—a region of space where an orbiting planet is not too close to its star to boil away all the water, and not so far away that the water is all frozen. This isn’t a fixed distance; it depends on the type and size of the star. With an enormous, hot star, the Goldilocks Zone would be much further away than Earth is from the Sun, and vice-versa for a smaller, cooler star. “That was a great first step, but it doesn’t make any distinctions within the habitable zone,” says Barnes.

Comparing a star's habitable zone based on its size. Credit: Fine Art America/Detlev Van Ravenswaay — Comparing a star’s habitable zone based on its size. Credit: Fine Art America/Detlev Van Ravenswaay.

Kepler has already confirmed the existence of over 1,000 exo-planets, with over 4,700 total candidate planets. And Kepler is still in operation. When it comes time to examine these planets more closely, with the James Webb Space Telescope and other instruments, where do we start? We needed a way to rank planets for further study. Enter Barnes and his team, and their habitability index.

To rank candidates for further study, Barnes focused on not just the distance between the planet and the host star, but on the overall energy equilibrium. That takes into account not just the energy received by the planet, but the planet’s albedo—how much energy it reflects back into space. In terms of being warm enough for life, a high-albedo planet can tolerate being closer to its star, whereas a low-albedo planet can tolerate a greater distance. This equilibrium is affected in turn by the eccentricity of the planet’s orbit.

The habitability index created by Barnes—and his colleagues Victoria Meadows and Nicole Evans—is a way to enter data, including a planet’s albedo and its distance from its host star, and get a number representing the planet’s probability of being habitable. “Basically, we’ve devised a way to take all the observational data that are available and develop a prioritization scheme,” said Barnes, “so that as we move into a time when there are hundreds of targets available, we might be able to say, ‘OK, that’s the one we want to start with.’”

So where does the Earth fit into all this? If alien astronomers are creating their own probability index, at 82%, Earth is a good candidate. Maybe they’re already studying us more closely.

February 4, 2016February 4, 2016 by Ken Kremer

First Atlas Launch of 2016 Set For Blastoff with Air Force GPS Satellite on Feb. 5 – Watch Live

ULA Atlas V carrying UASF GPS navigation satellite is poised for blastoff on Feb. 5, 2016 from Space Launch Complex-41 at Cape Canaveral Air Force Station, Florida. Newly installed crew access tower stands to right of Atlas rocket. Credit: Ken Kremer/kenkremer.com

CAPE CANAVERAL AIR FORCE STATION – The first launch of 2016 from Cape Canaveral, Florida, is poised for blastoff on Friday, Feb. 5, and features a United Launch Alliance Atlas V rocket carrying a US Air Force payload that will fortify the GPS constellation of navigation satellites that is critically important to military and civilian users on a 24/7 basis.

The commercial Atlas V rocket was rolled out to Space Launch Complex-41 at Cape Canaveral Air Force Station, Florida this morning, Thursday, Feb. 4. The USAF Global Positioning System GPS IIF-12 satellite is encapsulated in the 4 meter diameter nosecone. Continue reading “First Atlas Launch of 2016 Set For Blastoff with Air Force GPS Satellite on Feb. 5 – Watch Live”

February 4, 2016February 23, 2017 by Fraser Cain

What Are Alien Megastructures?

Did scientists find a giant alien structure around KIC 8462852? Probably not, but if they did, what would these structures look like?
Continue reading “What Are Alien Megastructures?”

February 4, 2016March 18, 2016 by Evan Gough

The Highest-Resolution Image Ever Seen in Astronomy

A jet of material being ejected out of a black hole at the centre of the galaxy BL Lacertae. Image: Dr. Jose L. Gomez

What do you get when you combine 15 radio telescopes on Earth and one in space? You get an enormous “virtual telescope” that is 63,000 miles across. And when you point it at a distant black hole, you get the highest resolution image every seen in astronomy.

Although it looks just like a big green blob, it’s actually an enormously energetic jet of matter streaming out of a black hole. And this black hole is 900 million light years away.

As reported at Popular Science, it required an array of 15 radio telescopes on Earth, and the Russian space telescope Spektr-R, to capture the image. This technique—called interferometry—is like creating a telescope that is 63,000 miles across. The detail it provides is like seeing a 50 cent coin on the Moon.

For perspective, the object in the image is 186 billion miles long, at minimum, and would just barely fit in the Oort Cloud.

The jet at the heart of BL Lacertae, with the Oort Cloud and Alpha Centauri for comparison. Image: Gomez et. al., A Lobanov, NRAO.

February 3, 2016March 18, 2016 by Evan Gough

China Shares Stunning New Moon Photos With the World

This image shows the Yutu rover leaving the lander area and making its way on the lunar surface. Image: Chinese Academy of Sciences/China National Space Administration/The Science and Application Centre for Moon and Deep Space Exploration/Emily Lakdawalla.

China has released hundreds of images of the Moon, taken by its Chang’e 3 lander and its companion rover, Yutu. It’s been 50 years since the first lunar photos were taken by astronauts on NASA’s Apollo 11 mission. China is the third nation to land on the Moon, with the USA and the USSR preceding them.

Even though the Yutu rover’s engine failed after a short time on the lunar surface, the mission’s camera systems have captured hundreds of images.

Thanks to the hard work of Emily Lakdawalla at The Planetary Society, who wrestled with a somewhat cumbersome Chinese website, and stitched some of these images together, we can get a first-hand look at what Chang’e 3 and Yutu were up to.

Here are some of our favourites.

Pyramid Rock, as named by the Chinese. This rock was ejected when the crater immediately behind it was created. Image: Chinese Academy of Sciences/China National Space Administration/The Science and Application Centre for Moon and Deep Space Exploration/Emily Lakdawalla.

This is a 360 degree panoramic image of the rover and part of the lander. Bright white rocks litter the rim of the crater on the left. Image: Chinese Academy of Sciences/China National Space Administration/The Science and Application Centre for Moon and Deep Space Exploration/Emily Lakdawalla.

The Yutu lander looks at its tracks in the lunar soil. Image: Chinese Academy of Sciences/China National Space Administration/The Science and Application Centre for Moon and Deep Space Exploration/Emily Lakdawalla.

This image shows a lot of detail of the Yutu rover. Image: Chinese Academy of Sciences/China National Space Administration/The Science and Application Centre for Moon and Deep Space Exploration/Emily Lakdawalla.

Emily Lakdawalla talks more about the camera systems here, and talks about what other images might be coming soon.

Universe Today reported on the Chinese Moon mission here.

February 3, 2016February 3, 2016 by Jason Major

50 Years Ago We Got Our First Picture from the Moon

The first image from the surface of the Moon via Luna 9, Feb. 3-4, 1966. (Credit: Roscosmos)

On this date half a century ago the Soviet Luna 9 spacecraft made humanity’s first-ever soft landing on the surface of the Moon. Launched from Baikonur on Jan. 31, 1966, Luna 9 lander touched down within Oceanus Procellarum — somewhere in the neighborhood of 7.08°N, 64.37°E* — at 18:44:52 UTC on Feb. 3. The fourth successful mission in the USSR’s long-running Luna series, Luna 9 sent us our first views of the Moon’s surface from the surface and, perhaps even more importantly, confirmed that a landing by spacecraft was indeed possible.

The entire Luna 9 lander was made up of two main parts: a 1,439-kg flight/descent stage which contained retro-rockets and orientation engines, navigation systems, and various fuel tanks, and a 99-kg (218-lb) pressurized “automatic lunar station” that contained all the science and imaging instruments along with batteries, heaters, and a radio transmitter.

When a probe on the descent stage detected contact with the lunar surface, the spherical station — encased in an inflated airbag — was jettisoned to soft-land a safe distance away — after a bit of bouncing, of course; the lander hit the Moon’s surface at about 22 km/hr (13 mph)!

The Luna 9 lunar station lander (NSSDC) — The Luna 9 lunar station lander. (NSSDC)

Once the airbag cushions deflated Luna 9, like a shiny metal flower, opened its four “petals,” extended its radio antennas and began taking panoramic television camera images of its surroundings, at the time lit by a very low Sun on the lunar horizon. Received on Earth early on Feb. 4, 1966, they were the first pictures taken from the surface of the Moon and in fact the first images acquired from the surface of another world.

Other missions, both Soviet and American, had captured close-up images of the Moon in previous years but Luna 9 was the first to soft-land (i.e., not crash land) and operate from the surface. The spacecraft continued transmitting image data to Earth until its batteries ran out on the night of Feb. 6, 1966. A total of four panoramas were acquired by Luna 9 over the course of three days, as well as data on radiation levels on the Moon’s surface (not to mention the valuable knowledge that a spacecraft wouldn’t just completely sink into the lunar regolith!)

Four months later, on June 2, 1966, NASA’s Surveyor 1 would become the first U.S. spacecraft to soft-land on the Moon. Surveyor 1 would send back science data and 11,240 photos over the course of a month in operation but, in terms of the space “race,” Luna 9 will always be remembered as first place winner.

Want to see more pictures from Luna 9 and other Soviet Moon missions? Check out Don P. Mitchell’s dedicated page here, and learn more about the Luna program on Robert Christy’s Zarya site.

Sources: NASA/NSSDC, LPI, Robert Christy/Zarya

*Or is it 7.14°N/60.36°W? Even today it’s still not precisely known where Luna 9 landed, but researchers at Arizona State University are actively searching through Lunar Reconnaissance Orbiter Camera pictures in an attempt to spot the “lost” spacecraft and/or evidence of its historic landing. Read more about that here.

February 3, 2016 by David Dickinson

A Challenge in Visual Athletics: Hunting the Gegenschein

The gegenschein visible as the bright 'knot' in the zodiacal glow high above the VLT. Image credit: ESO/Y. Beletsky

Looking for something truly elusive? Astronomy has no shortage of the fleeting and ephemeral when it comes to challenges. This week’s challenge will require supremely dark skies and persistence.

We’re talking about the gegenschein, the elusive counter glow lying opposite to the Sun across the plane of the ecliptic. Continue reading “A Challenge in Visual Athletics: Hunting the Gegenschein”

February 2, 2016March 18, 2016 by Evan Gough

A Cataclysmic Collision Formed the Moon, but Killed Theia

Artist's impression of a Mars-sized object crashing into the Earth, starting the process that eventually created our Moon. Credit: Joe Tucciarone

The Moon is the first object in space that fascinates we Earthlings. The Sun might be more prominent, but you can’t stare at the Sun without ocular damage. Anyone can gaze at the Moon, with or without binoculars or a telescope, and wonder where it came from and what it all means.

New evidence from a team at UCLA is clarifying the story of the Moon’s origins. According to this research, the Moon was formed as a result of a massive collision between Earth and a “planet embryo” about the size of Mars called Theia. This collision happened about 100 million years after the Earth was formed. Published on January 29th in the journal Science, this new geological evidence strengthens the case for the collision model.

The researchers compared Earth rocks with rocks retrieved from the Moon over the years. (Over 380kg of rocks have been brought back to Earth.) They found that these samples—collected on Apollo missions 12, 15, and 17—had the same chemical composition as seven rocks collected from Earth’s mantle, in Hawaii and Arizona. The key to the comparison lies in the nature of the oxygen atoms in the rocks.

Oxygen is a highly reactive element. It is easily combined with other elements, and is the most common element in the Earth’s crust. There are several different oxygen isotopes present in the Earth’s crust, and on other bodies in the solar system. The amount of each isotope present on each body is the “fingerprint” that makes the formation of each body different.

But the team at UCLA has shown that Earth and the Moon share the same cocktail of oxygen isotopes. They have the same fingerprint. This means that somehow, someway, their formation is linked. It can’t be pure coincidence. Says Edward Young, lead author of the new study, “We don’t see any difference between the Earth’s and the Moon’s oxygen isotopes; they’re indistinguishable.”

So how did this happen? How do Earth and the Moon share the same oxygen fingerprint? Enter Theia, an embryonic planet that got in the way of Earth’s orbit around the Sun. And as the research shows, this collision had to be more than a glancing blow. The collision had to be direct and cataclysmic.

This video shows how the collision would have played out.

A glancing blow would mean that the Moon would be mostly made of Theia, and would therefore have a different oxygen isotope fingerprint than Earth. But the fact that the Earth and Moon are indistinguishable from each other means that Theia had to have been destroyed, or rather, had to become part of both the Earth and the Moon.

“Theia was thoroughly mixed into the Earth and the Moon, and evenly dispersed between them. This explains why we don’t see a different signature of Theia in the Moon versus Earth,” said Young.

If this collision had not taken place, our Solar System would look very different, with an additional rocky planet in the inner regions. We also would have no Moon, which would have changed the evolution of life on Earth.

This collision theory, called the Theia Impact, or the Big Splash, has been around since 2012. But in 2014, a team of German researchers reported in Science that the Earth and Moon have different oxygen isotope ratios, which threw the collision formation theory into doubt. These new results confirm that it was a cataclysmic collision that gave birth to the Moon, and changed our Solar System forever.

February 2, 2016February 2, 2016 by Ken Kremer

NASA’s Orion Crew Module Backbone Arrives at KSC Aboard Super Guppy for Exploration Mission-1

NASA’s Orion EM-1 crew module pressure vessel arrived at the Kennedy Space Center’s Shuttle Landing Facility tucked inside NASA’s Super Guppy aircraft on Feb 1, 2016. The Super Guppy opens its hinged nose to unload cargo. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER – Looking amazingly like a fish flying across the skies high above the Florida space coast, NASA’s unique Super Guppy aircraft loaded with the structural backbone for NASA’s next Orion crew module, swooped in for a landing at the Kennedy Space Center on Monday afternoon, Feb. 1.

The Super Guppy, with the recently completed pressure vessel for the Orion crew module tucked safely inside, touched down gently at about 3:45 p.m. Monday on the same runway at the Shuttle Landing Facility (SLF) where NASA’s now retired orbiters formerly returned from space voyages. The landing strip is now operated by Space Florida. Continue reading “NASA’s Orion Crew Module Backbone Arrives at KSC Aboard Super Guppy for Exploration Mission-1”