Posted on by Elizabeth Howell

How Many Moons Does Venus Have?

A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL

There are dozens upon dozens of moons in the Solar System, ranging from airless worlds like Earth’s Moon to those with an atmosphere (most notably, Saturn’s Titan). Jupiter and Saturn have many moons each, and even Mars has a couple of small asteroid-like ones. But what about Venus, the planet that for a while, astronomers thought about as Earth’s twin?

The answer is no moons at all. That’s right, Venus (and the planet Mercury) are the only two planets that don’t have a single natural moon orbiting them. Figuring out why is one question keeping astronomers busy as they study the Solar System.

Astronomers have three explanations about how planets get a moon or moons. Perhaps the moon was “captured” as it drifted by the planet, which is what some scientists think happened to Phobos and Deimos (near Mars). Maybe an object smashed into the planet and the fragments eventually coalesced into a moon, which is the leading theory for how Earth’s Moon came together. Or maybe moons arose from general accretion of matter as the solar system was formed, similar to how planets came together.

The International Space Station captured as it passed in front of the Moon on Dec. 6, 2013, as seen from Puerto Rico. Credit and copyright: Juan Gonzalez-Alicea.
The International Space Station captured as it passed in front of the Moon on Dec. 6, 2013, as seen from Puerto Rico. Credit and copyright: Juan Gonzalez-Alicea.

Considering the amount of stuff flying around the Solar System early in its history, it’s quite surprising to some astronomers that Venus does not have a moon today. Perhaps, though, it had one in the distant past. In 2006, California Institute of Technology researchers Alex Alemi and David Stevenson presented at the American Astronomical Society’s division of planetary sciences meeting and said Venus could have been smacked by a large rock at least twice. (You can read the abstract here.)

“Most likely, Venus was slammed early on and gained a moon from the resulting debris. The satellite slowly spiraled away from the planet, due to tidal interactions, much the way our Moon is still slowly creeping away from Earth,” Sky and Telescope wrote of the research.

“However, after only about 10 million years Venus suffered another tremendous blow, according to the models. The second impact was opposite from the first in that it ‘reversed the planet’s spin,’ says Alemi. Venus’s new direction of rotation caused the body of the planet to absorb the moon’s orbital energy via tides, rather than adding to the moon’s orbital energy as before. So the moon spiraled inward until it collided and merged with Venus in a dramatic, fatal encounter.”

Venus as photographed by the Pioneer spacecraft in 1978. Some exoplanets may suffer the same fate as this scorched world. Credit: NASA/JPL/Caltech
Venus as photographed by the Pioneer spacecraft in 1978. Some exoplanets may suffer the same fate as this scorched world. Credit: NASA/JPL/Caltech

There could be other explanations as well, however, which is part of why astronomers are so interested in revisiting this world. Figuring out the answer could teach us more about the solar system’s formation.

To learn more about Venus, check out these links:

Venus (NASA)
Venus Express (European Space Agency spacecraft currently at the planet)
Venus (Astronomy Cast)
Venus (Windows To The Universe)
Venus Crater Database (Lunar and Planetary Institute)
Magellan Mission to Venus (NASA)
Chasing Venus (Smithsonian)

Posted on by Elizabeth Howell

How Far Are The Planets From The Sun?

Artist's impression of the planets in our solar system, along with the Sun (at bottom). Credit: NASA

The eight planets in our solar system each occupy their own orbits around the Sun. They orbit the star in ellipses, which means their distance to the sun varies depending on where they are in their orbits. When they get closest to the Sun, it’s called perihelion, and when it’s farthest away, it’s called aphelion.

So to talk about how far the planets are from the sun is a difficult question, not only because their distances constantly change, but also because the spans are so immense — making it hard for a human to grasp. For this reason, astronomers often use a term called astronomical unit, representing the distance from the Earth to the Sun.

The table below (first created by Universe Today founder Fraser Cain in 2008) shows all the planets and their distance to the Sun, as well as how close these planets get to Earth.

Mercury:

Closest: 46 million km / 29 million miles (.307 AU)
Farthest: 70 million km / 43 million miles (.466 AU)
Average: 57 million km / 35 million miles (.387 AU)
Closest to Mercury from Earth: 77.3 million km / 48 million miles

Venus:

Closest: 107 million km / 66 million miles (.718 AU)
Farthest: 109 million km / 68 million miles (.728 AU)
Average: 108 million km / 67 million miles (.722 AU)
Closest to Venus from Earth: 40 million km / 25 million miles

The planet Venus, as imaged by the Magellan 10 mission. Credit: NASA/JPL
The planet Venus, as imaged by the Magellan 10 mission. Credit: NASA/JPL

Earth:

Closest: 147 million km / 91 million miles (.98 AU)
Farthest: 152 million km / 94 million miles (1.01 AU)
Average: 150 million km / 93 million miles (1 AU)

Mars:

Closest: 205 million km / 127 million miles (1.38 AU)
Farthest: 249 million km / 155 million miles (1.66 AU)
Average: 228 million km / 142 million miles (1.52 AU)
Closest to Mars from Earth: 55 million km / 34 million miles

Jupiter:

Closest: 741 million km /460 million miles (4.95 AU)
Farthest: 817 million km / 508 million miles (5.46 AU)
Average: 779 million km / 484 million miles (5.20 AU)
Closest to Jupiter from Earth: 588 million km / 346 million miles

Jupiter and Io. Image Credit: NASA/JPL
Artist’s impression of Jupiter and Io. Credit: NASA/JPL

Saturn:

Closest: 1.35 billion km / 839 million miles (9.05 AU)
Farthest: 1.51 billion km / 938 million miles (10.12 AU)
Average: 1.43 billion km / 889 million miles (9.58 AU)
Closest to Saturn from Earth: 1.2 billion km /746 million miles

Uranus:

Closest: 2.75 billion km / 1.71 billion miles (18.4 AU)
Farthest: 3.00 billion km / 1.86 billion miles (20.1 AU)
Average: 2.88 billion km / 1.79 billion miles (19.2 AU)
Closest to Uranus from Earth: 2.57 billion km / 1.6 billion miles

Neptune:

Closest: 4.45 billion km /2.77 billion miles (29.8 AU)
Farthest: 4.55 billion km / 2.83 billion miles (30.4 AU)
Average: 4.50 billion km / 2.8 billion miles (30.1 AU)
Closest to Neptune from Earth: 4.3 billion km / 2.7 billion miles

As a special bonus, we’ll include Pluto too, even though Pluto is not a planet anymore.

Uranus and Neptune, the Solar System’s ice giant planets. (Images from Wikipedia.)
Uranus and Neptune, the Solar System’s ice giant planets. Credit: Wikipedia Commons

Pluto:

Closest: 4.44 billion km / 2.76 billion miles (29.7 AU)
Farthest: 7.38 billion km / 4.59 billion miles (49.3 AU)
Average: 5.91 billion km / 3.67 billion miles (39.5 AU)
Closest to Pluto from Earth: 4.28 billion km / 2.66 billion miles

To learn more:

Online resources demonstrating the scale of the Solar System:

If The Moon Were Only A Pixel (Josh Worth Art & Design)
Scale Model Of Our Solar System (University of Manitoba)
Build A Solar System (Exploratorium)
Scale Solar System (Josh Wetenkamp)

Many cities and countries have also installed scale models of the Solar System, such as:

Voyage Scale Solar System (Washington, D.C.)
Sagan Planet Walk (Ithaca, N.Y.)
Maine Solar System Model
Sweden Solar System
Planet Walk (Munich, Germany)
The Solar System (Brittany, France; website in French only)
Solar System Drive (Australia)

Posted on by Elizabeth Howell

The Planets in Our Solar System in Order of Size

Planets in our Solar system size comparison. Largest to smallest are pictured left to right, top to bottom: Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury. Via Wikimedia Commons.

If you’re interested in planets, the good news is there’s plenty of variety to choose from in our own Solar System. From the ringed beauty of Saturn, to the massive hulk of Jupiter, to the lead-melting temperatures on Venus, each planet in our solar system is unique — with its own environment and own story to tell about the history of our Solar System.

What also is amazing is the sheer size difference of planets. While humans think of Earth as a large planet, in reality it is dwarfed by the massive gas giants lurking at the outer edges of our Solar System. This article explores the planets in order of size, with a bit of context as to how they got that way.

A Short History of the Solar System:

No human was around 4.5 billion years ago when the Solar System was formed, so what we know about its birth comes from several sources: examining rocks on Earth and other places, looking at other solar systems in formation and doing computer models, among other methods. As more information comes in, some of our theories of the Solar System must change to suit the new evidence.

Today, scientists believe the Solar System began with a spinning gas and dust cloud. Gravitational attraction at its center eventually collapsed to form the Sun. Some theories say that the young Sun’s energy began pushing the lighter particles of gas away, while larger, more solid particles such as dust remained closer in.

Artist's conception of a solar system in formation. Credit: NASA/FUSE/Lynette Cook
Artist’s conception of a solar system in formation. Credit: NASA/FUSE/Lynette Cook

Over millions and millions of years, the gas and dust particles became attracted to each other by their mutual gravities and began to combine or crash. As larger balls of matter formed, they swept the smaller particles away and eventually cleared their orbits. That led to the birth of Earth and the other eight planets in our Solar System. Since much of the gas ended up in the outer parts of the system, this may explain why there are gas giants — although this presumption may not be true for other solar systems discovered in the universe.

Until the 1990s, scientists only knew of planets in our own Solar System and at that point accepted there were nine planets. As telescope technology improved, however, two things happened. Scientists discovered exoplanets, or planets that are outside of our solar system. This began with finding massive planets many times larger than Jupiter, and then eventually finding planets that are rocky — even a few that are close to Earth’s size itself.

The other change was finding worlds similar to Pluto, then considered the Solar System’s furthest planet, far out in our own Solar System. At first astronomers began treating these new worlds like planets, but as more information came in, the International Astronomical Union held a meeting to better figure out the definition.

Hubble image of Pluto and some of its moons, Charon, Nix and Hydra. Image Credit: NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI), and the HST Pluto Companion Search Team
Hubble image of Pluto and some of its moons, Charon, Nix and Hydra. Image Credit: NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI), and the HST Pluto Companion Search Team

The result was redefining Pluto and worlds like it as a dwarf planet. This is the current IAU planet definition:

“A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit.”

Size of the Eight Planets:

According to NASA, this is the estimated radii of the eight planets in our solar system, in order of size. We also have included the radii sizes relative to Earth to help you picture them better.

  • Jupiter (69,911 km / 43,441 miles) – 1,120% the size of Earth
  • Saturn (58,232 km / 36,184 miles) – 945% the size of Earth
  • Uranus (25,362 km / 15,759 miles) – 400% the size of Earth
  • Neptune (24,622 km / 15,299 miles) – 388% the size of Earth
  • Earth (6,371 km / 3,959 miles)
  • Venus (6,052 km / 3,761 miles) – 95% the size of Earth
  • Mars (3,390 km / 2,460 miles) – 53% the size of Earth
  • Mercury (2,440 km / 1,516 miles) – 38% the size of Earth
Eight planets and a dwarf planet in our Solar System, approximately to scale. Pluto is a dwarf planet at far right. At far left is the Sun. The planets are, from left, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Credit: Lunar and Planetary Institute
Eight planets and a dwarf planet in our Solar System, approximately to scale. Pluto is a dwarf planet at far right. At far left is the Sun. The planets are, from left, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Credit: Lunar and Planetary Institute

Jupiter is the behemoth of the Solar System and is believed to be responsible for influencing the path of smaller objects that drift by its massive bulk. Sometimes it will send comets or asteroids into the inner solar system, and sometimes it will divert those away.

Saturn, most famous for its rings, also hosts dozens of moons — including Titan, which has its own atmosphere. Joining it in the outer solar system are Uranus and Neptune, which both have atmospheres of hydrogen, helium and methane. Uranus also rotates opposite to other planets in the solar system.

The inner planets include Venus (once considered Earth’s twin, at least until its hot surface was discovered); Mars (a planet where liquid water could have flowed in the past); Mercury (which despite being close to the sun, has ice at its poles) and Earth, the only planet known so far to have life.

To learn more about the Solar System, check out these resources:

Planets (NASA)
Solar System (USGS)
Exploring the Planets (National Air and Space Museum)
Windows to the Universe (National Earth Science Teachers Association)
Solar System (National Geographic, requires free registration)

Posted on by Fraser Cain

What Happens When The Poles Flip?

What Happens When The Poles Flip?

Have you heard the terrifying news that the Earth’s poles are going to flip? What does “flipping” mean? And if the Earth’s poles do flip, are we in any danger?

Have you heard the startling news that the Earth’s poles might flip? Perhaps in the response to a close pass from the mysterious Planet X? Are you imagining the entire Earth actually flipping over on its side or rotating upside down, possibly while Yakkity Sax plays in the background? When will this happen? Can this happen?

First, there’s no secret planet hurtling through the Solar System causing chaos and orbital disturbances. So could the Earth spontaneously physically flip over? Some planets have already been tilted and flipped.

Take a look at Uranus. Its orbital tilt is 98-degrees. We assume the planet started with the same tilt as the rest of the Solar System, and some event in the ancient past caused it to fall over. It could have collided with another planet, billions of years ago, or gravitational interactions with other giant planets pushed it over.

And then there’s Venus, its axial tilt is 177-degrees. That’s essentially upside down. Venus is turning in the opposite direction from every other planet in the Solar System. Standing on the surface of Venus, you would see the Sun rise in the West and set in the East. Astronomers don’t know why this happened, perhaps it was gravitational interactions or a collision with another planet.

To actually flip a planet off its axis would take an event so catastrophic that it would devastate the planet. Don’t worry, as far as we know, those kinds of events and interactions stopped happening billions of years ago.
That’s the good news. The Earth isn’t likely to just fall over, or get bashed on its side like an office tower under the might of Godzilla

Schematic illustration of Earth's magnetic field. Credit/Copyright: Peter Reid
Schematic illustration of Earth’s magnetic field. Credit/Copyright: Peter Reid

Now what about those magnetic poles. On Earth, they can and do reverse on a regular basis. The Earth is often shown like a giant bar magnet, with a north magnetic pole and a south magnetic pole. Over vast periods of time, the Earth’s north pole becomes its south pole, and vice versa. Geologists measure the magnetic configuration of iron particles in ancient lava flows. in one part of the lava flow, the particles oriented with one magnetic configuration, and then in another, the particles were reversed. It turns out the planet reverses its polarity every 450,000 years, and the last reversal happened about 780,000 years ago. Which means it could happen in the next few thousand years.

If the Earth’s poles did reverse, what would happen to us? If the magnetic field disappeared entirely, the planet would be bathed in radiation from the Sun, which would likely cause an increase in cancer. But the Earth’s atmosphere would still protect us from majority of radiation.

What about mass extinctions? Scientists have wondered if there’s a link between them and magnetic reversals.
Fortunately for us, there doesn’t seem to be any connection. Whenever geomagnetic reversals happened in the past, it didn’t devastate life on Earth. So don’t worry about it.

There is a pretty good chance it won’t happen in our lifetime, and maybe not for hundreds of thousands of years. And even if the Earth’s poles flip, it wouldn’t be the end of the world. You might need to take a sharpie to your compass though.

Posted on by Bob King

New Comet Jacques May Pass 8.4 million miles from Venus this July

Comet C/2014 E2 Jacques photographed from Siding Spring Observatory on March 14, 2014. Credit: Rolando Ligustri

Congratulations to Cristovao Jacques and the SONEAR team!  On March 13 they snared C/2014 E2 (Jacques) in CCD images taken with a 0.45-meter (17.7-inch) wide-field reflector at the SONEAR (Southern Observatory for Near Earth Asteroids Research) observatory near Oliveira, Brazil. A very preliminary orbit indicates its closest approach to the sun will occur on June 29 at a distance of 56 million miles followed two weeks later by a relatively close flyby of Venus of 0.09 a.u. or  8.4 million miles (13.5 million km). If a comet approached Earth this closely so soon after perihelion, it would be a magnificent sight. Of course, watching from Venus isn’t recommended. Even if we could withstand its extreme heat and pressure cooker atmosphere, the planet’s perpetual cloud cover guarantees overcast skies 24/7.

Comet Jacques travels across the deep southern sky in early spring as seen from mid-northern latitudes
Comet Jacques travels across the deep southern sky in early spring as seen from mid-northern latitudes. Approximate positions are shown through April 4. Stellarium

It’s the team’s second comet discovery this year after turning up C/2014 A4 (SONEAR) in January. Comet Jacques has been tracking across northern Centaurus since discovery. Over the next few nights, it straddles the border with Hydra where it will be visible low in the southern sky around for northern hemisphere observers from about midnight to 2 a.m. If you live on a Caribbean island and points south your view will be even better.


Steven Tilley’s animation of Comet C/2014 E2 Jacques over 35 minutes on March 13, 2014

Comet Jacques exhibits a dense, fairly bright 2-arc-minute coma or cometary atmosphere with a short northward-pointing tail. Brightness estimates have been hard to come by, but it appears the comet may be around magnitude +11.5 – 12 or within range of an 8-inch (20-cm) or larger telescope. One thing’s for certain. In the coming weeks, E2 will be approaching both the Earth and the sun and brightening as it slowly gains altitude in the evening sky.

Another view of the comet on March 13 through a 0.5-meter (19.5-inch) telescope. Credit: Ernesto Guido, Nick Howes, Martino Nicolini
Another view of the comet on March 13 through a 0.5-meter (19.5-inch) telescope. Credit: Ernesto Guido, Nick Howes, Martino Nicolini

Shortly after perihelion, Comet Jacques will shine brightest at around magnitude +10-10.5 (though it could be brighter) and remain nearly this bright as it swings north from Orion into Perseus from mid-July to mid- August. Closest approach to Earth occurs on Aug. 29-30 at 54 million miles (87 million km). It will join Comet Oukameiden – predicted to reach binocular visibility in late August – to offer comet lovers much to look forward to as the summer wanes.

Posted on by Nancy Atkinson

‘Rainbow’ on Venus Seen for First Time

False colour composite of a rainbow-like feature known as a ‘glory’, seen on Venus on 24 July 2011. The image is composed of three images at ultraviolet, visible, and near-infrared wavelengths from the Venus Monitoring Camera. The images were taken 10 seconds apart and, due to the motion of the spacecraft, do not overlap perfectly. The glory is 1200 km across, as seen from the spacecraft, 6000 km away. It's the only glory ever seen on another planet. Credit: ESA/MPS/DLR/IDA.

Oh glory! A rainbow-like optical phenomenon known as a ‘glory’ has been imaged for the first time on another planet. It was seen in the atmosphere of our nearest neighbor, Venus by ESA’s Venus Express orbiter.

Rainbows and glories occur when sunlight shines on cloud droplets. While rainbows arch across the sky, glories appear as circular rings of colored concentric rings centered on a bright core.

Glory with aircraft shadow in the center. Via Wikimedia Commons.
Glory with aircraft shadow in the center. Via Wikimedia Commons.

Glories are only seen when the observer is situated directly between the Sun and the cloud particles that are reflecting sunlight. On Earth, they can often be seen with the naked eye from airplanes, or when looking down upon fog or water vapor, such as when climbing a mountain.

On Earth, the simple ingredients needed for a rainbow are sunlight and raindrops. On Venus, the droplets are likely made of sulfuric acid.

Three images showing the glory at ultraviolet (left,) visible (centre) and near-infrared (right) wavelengths as taken by the Venus Monitoring Camera. The feature was observed on 24 July 2011 and measures 1,200 km across, as seen from the spacecraft, 6,000 km away. Credit: ESA/MPS/DLR/IDA.
Three images showing the glory at ultraviolet (left,) visible (centre) and near-infrared (right) wavelengths as taken by the Venus Monitoring Camera. The feature was observed on 24 July 2011 and measures 1,200 km across, as seen from the spacecraft, 6,000 km away. Credit: ESA/MPS/DLR/IDA.

Seeing this glory was no accident: they made a calculated effort to image the clouds with the Sun directly behind the Venus Express spacecraft. The scientists were hoping to spot a glory in order to determine important characteristics of the cloud droplets.

Today, the team reported that they were successful. The glory in the images here was seen at the Venus cloud tops, 70 km above the planet’s surface, back on July 24, 2011. Their paper was just recently accepted for publication.

The glory was 1,200 km wide as seen from the spacecraft, 6,000 km away.

The Venus Express team deduced that from these observations, the cloud particles are estimated to be 1.2 micrometres across, roughly a fiftieth of the width of a human hair.

The fact that the glory is 1,200 km wide means that the particles at the cloud tops are uniform on this scale at least.

The variations of brightness of the rings of the observed glory is different than that expected from clouds of only sulphuric acid mixed with water, suggesting that other chemistry may be at play.

One idea is that the cause is the “UV-absorber,” an unknown atmospheric component responsible for mysterious dark markings seen in the cloud tops of Venus at ultraviolet wavelengths. More investigation is needed to draw a firm conclusion.

Scientists also think that it would be possible to see a rainbow — and perhaps even a glory — on Titan since the atmosphere on this moon of Saturn is likely filled with methane droplets.

Source: ESA

Posted on by Nancy Atkinson

Astrophotographer’s Dream: Venus and Milky Way Galaxy Over Singapore

Rise of Venus and the Milky Way in Singapore on Feb. 28, 2014. Credit and copyright: Justin Ng.

“My dream to capture the beautiful Milky Way galaxy in Singapore has finally come true this morning after the monsoon season is over,” said noted astrophotographer Justin Ng, who lives in this island country in South East Asia. Justin noted that since Singapore is known for its heavy light pollution, there are many people who believe it’s impossible to capture stars and the arc of the Milky Way under those conditions. Justin has been taking amazing deep sky and night sky photos for quite some time, but he said with this particular image he’s hoping to prove the naysayers wrong.

“Plus, I hope to inspire more astrophotographers residing in heavily light polluted city to try to capture these ‘impossible’ images,” Justin added.

UPDATE: Below is a new timelapse video from Justin Ng.

This is a single exposure shot of planet Venus and Milky Way Galaxy in Singapore. However, the light pollution near the horizon is also visible.

Justin has now created a timelapse of his Milky Way photography from the same night he took this image, and he says a timelapse like this never been attempted by any photographers in Singapore, this is is the first:

Rise of Milky Way and Venus in Singapore from Justin Ng Photo on Vimeo.

You can see more of Justin’s fantastic astrophotography at his website, on G+, Facebook and Twitter.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Posted on by Fraser Cain

Virtual Star Party – February 23, 2014 – Nebulae, Sunspots, and Planet “X”?!?

Hosts: Fraser Cain & Scott Lewis
Astronomers: David Dickinson, Gary Gonella, James McGee, Mike Simmons, Roy Salisbury, Shahrin Ahmad, Tom Nathe

Tonight’s views:
Jupiter with a nice view of the red spot, Venus approaching zenith, Bubble Nebula, the Pleiades, Orion Nebula, Horsehead Nebula, Flame Nebula, Running Man Nebula, the Moon, the Sun, the ISS (photo), the Rosette Nebula, Orion again, M33, Sunspots, Rosette again, California Nebula (multiple views), M81 & M82, Planet “X” (?!?), Andromeda, Flame Nebula again

We hold the Virtual Star Party every Sunday night as a live Google+ Hangout on Air. We begin the show when it gets dark on the West Coast. If you want to get a notification, make sure you circle the Virtual Star Party on Google+. You can watch on our YouTube channel or here on Universe Today.

Posted on by Fraser Cain

Weekly Space Hangout – February 7, 2014: New Impact on Mars & A Wobbly Planet

Host: Fraser Cain
Astrojournalists: Scott Lewis, Nicole Gugliucci, Morgan Rehnberg, Brian Koberlein, Elizabeth Howell, Amy Shira Teitel, David Dickinson

This Week’s Stories!

Morgan Rehnberg (cosmicchatter.org / @cosmic_chatter):
New Mars impact crater

Nicole Gugliucci (cosmoquest.org / @noisyastronomer):
Weird Asteroid Itokawa Has a Dual Personality
Shiny new radio image of M82 (but no supernova afterglow)

David Dickinson (@astroguyz):
Venus in 2014
Progress+launches for February
Space History-Curious Artifacts Sent Into Space

Elizabeth Howell (@howellspace):
Astronomy Podcast Enters Sixth Year — And We’d Love For You To Contribute!
Super-Earths Could Be More ‘Superhabitable’ Than Planets Like Ours

Brian Koberlein (@briankoberlein); Scott Lewis (@baldastronomer); & Elizabeth Howell (@howellspace):
‘Wobbly’ Alien Planet Has Weird Seasons And Orbits Two Stars

Amy Shira Teitel (@astVintageSpace):
When galaxies collide!

Scott Lewis (@baldastronomer):
Gaia

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.