A Red Moon – NOT a Sign of the Apocalypse!

Composite picture of a dark red Moon during a total lunar eclipse. Credit: NASA/ Johannes Schedler (Panther Observatory)

On most evenings, the Moon will appear as a bright yellow or white color in the night sky. But on occasion, the Moon can turn a beautiful and dramatic red, coppery color. Naturally, there are a number of superstitions associated with this stellar event. But to modern astronomers, a Red Moon is just another fascinating phenomenon that has a scientific explanation.

Since the earliest days of recorded history, the Moon has been believed to have a powerful influence over human and animal behavior. To the Romans, staring at a full Moon was thought to drive a person crazy – hence the term “lunatic”. Farmers in the past would plant their crops “by the moon”, which meant sowing their seeds in accordance with the Moon’s phases in the hopes of getting a better harvest.

So naturally, when the Moon turned red, people became wary. According to various Biblical passages, a Blood Moon was thought to be a bad omen. But of course, the Moon turns red on a semi-regular basis, and the world has yet to drown in fire. So what really accounts for a “Red Moon?” What causes Earth’s only satellite to turn the color of blood?

Ordinarily, the Moon appears as it does because it is reflecting light from the Sun. But on occasion, it will darken and acquire either a golden, copper, or even rusty-red color.

There are few situations that can cause a red Moon. The most common way to see the Moon turn red is when the Moon is low in the sky, just after moonrise or before it’s about to set below the horizon. Just like the Sun, light from the Moon has to pass through a larger amount of atmosphere when it’s down near the horizon, compared to when it’s overhead.

The Earth’s atmosphere can scatter sunlight, and since moonlight is just scattered sunlight, it can scatter that too. Red light can pass through the atmosphere and not get scattered much, while light at the blue end of the spectrum is more easily scattered. When you see a red moon, you’re seeing the red light that wasn’t scattered, but the blue and green light have been scattered away. That’s why the Moon looks red.

The second reason for a red Moon is if there’s some kind of particle in the air. A forest fire or volcanic eruption can fill the air with tiny particles that partially obscure light from the Sun and Moon. Once again, these particles tend to scatter blue and green light away, while permitting red light to pass through more easily. When you see a red moon, high up in the sky, it’s probably because there’s a large amount of dust in the air.

Depiction of the Sun's rays turning the Moon red. Image Credit: NASA/Mars Exploration
Depiction of the Sun’s rays turning the Moon red. Image Credit: NASA/Mars Exploration

A third – and dramatic – way to get a red Moon is during a lunar eclipse. This happens when the Moon is full and passes into Earth’s shadow (also known as the umbra), which darkens it. At that point, the Moon is no longer being illuminated by the Sun. However, the red light passing through the Earth’s atmosphere does reach the Moon, and is thus reflected off of it.

For those observing from the ground, the change in color will again be most apparent when the Moon appears low in the night sky, just after moonrise or before it’s about to set below the horizon. Once again, this is because our heavy atmosphere will scatter away the blue/green light and let the red light go straight through.

The reddish light projected on the Moon is much dimmer than the full white sunlight the Moon typically reflects back to us. That’s because the light is indirect and because the red-colored wavelengths are only a part of what makes up the white light from the sun that the Moon usually receives.

In other words, when you see a red Moon, you’re seeing the result of blue and green light that has been scattered away, and the red light remaining.

Path of the Moon through Earth's umbral and penumbral shadows during the Total Lunar Eclipse of April 15, 2014. Image Credit: NASA/Eclipse
Path of the Moon through Earth’s umbral and penumbral shadows during the Total Lunar Eclipse of April 15, 2014. Image Credit: NASA/Eclipse Website

And that’s the various ways how we get a Red Moon in the night sky. Needless to say, our ancient forebears were a little nervous about this celestial phenomenon occurrence.

For example, Revelations 6:12/13 says that a Red Moon is a sign of the apocalypse: “When he opened the sixth seal, I looked, and behold, there was a great earthquake, and the sun became black as sackcloth, the full moon became like blood, and the stars of the sky fell to the earth as the fig tree sheds its winter fruit when shaken by a gale.”

But rest assured that if you see one, it’s not the end of the world. The Sun and Moon will rise again. And be sure to check out this Weekly Space Hangout, where the April 4th eclipse is discussed:

We have covered lunar eclipses many times on Universe Today, and often explain the red Moon phenomenon. Here’s another good explanation of the science behind a Red Moon, and why the recent series of lunar eclipses in 2014 and 2015 (known as a tetrad) do not mean anything apocalyptic, and here’s another article about how to see a lunar eclipse. Here’s an article that includes a stunning array of images of the Moon during an eclipse in 2014.

Of course, NASA has some great explanations of the red Moon effect during a lunar eclipse. Here’s another one.

You can listen to a very interesting podcast about the formation of the Moon from Astronomy Cast, Episode 17: Where Did the Moon Come From?

Sources: NASA Science: Lunar Eclipse, NASA: Mars Exploration, Discovery News, NASA: Eclipse Website

Surprise – Mars Has Auroras Too!

Artist’s conception of MAVEN’s Imaging UltraViolet Spectrograph observing the “Christmas Lights Aurora" on Mars. (University of Colorado)

Just a day after skywatchers at mid- to upper-latitudes around the world were treated to a particularly energetic display of auroras on the night of March 17 as a result of an intense geomagnetic storm, researchers announced findings from NASA’s MAVEN mission of auroral action observed on Mars – although in energetic ultraviolet wavelengths rather than visible light.

Detected by MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument over five days before Dec. 25, 2014, the ultraviolet auroras have been nicknamed Mars’ “Christmas lights.” They were observed across the planet’s mid-northern latitudes and are the result of Mars’ atmosphere interacting directly with the solar wind.

Map of the UV aurora detected on Mars in Dec. 2014 (University of Colorado)
Map of the UV aurora detected on Mars in Dec. 2014 (University of Colorado)

While auroras on Earth typically occur at altitudes of 80 to 300 kilometers (50 to 200 miles) and occasionally even higher, Mars’ atmospheric displays were found to be much lower, indicating higher levels of energy.

“What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs – much deeper than at Earth or elsewhere on Mars,” said Arnaud Stiepen, IUVS team member at the University of Colorado. “The electrons producing it must be really energetic.”

To a human observer on Mars the light show probably wouldn’t be very dramatic, though. Without abundant amounts of oxygen and nitrogen in its thin atmosphere a Martian aurora would be a dim blue glow at best, if not out of the visible spectrum entirely.

This isn’t the first time auroras have been spotted on Mars; observations with ESA’s Mars Express in 2004 were actually the first detections of the phenomenon on the Red Planet. Made with the spacecraft’s SPICAM ultraviolet spectrometer, the observations showed that Mars’ auroras are unlike those found anywhere else in the Solar System in that they are generated by particle interactions with very localized magnetic field emissions, rather than a globally-generated one (like Earth’s).

(So no, it’s not a total surprise… but it’s still very cool!)

In addition to auroras MAVEN also detected diffuse but widespread dust clouds located surprisingly high in the Martian atmosphere. It’s not yet understood what process is delivering dust so high – 150-300 kilometers up (93-186 miles) – or if it is a permanent or temporary feature.

Read more in the MAVEN news release here.

Source: NASA and Nature

 

 

Why Is Venus So Horrible?

Why Is Venus So Horrible?

Venus really sucks. It’s as hot as an oven with a dense, poisonous atmosphere. But how did it get that way?

Venus sucks. Seriously, it’s the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you dead in moments.

Let’s push Venus into the Sun and be done with that terrible place. Its proximity is lowering our real estate values and who knows what sort of interstellar monstrosities are going to set up shop there, and be constantly knocking on our door to borrow the mower, or a cup or sugar, or sneak into our yard at night and eat all our dolphins.

You might argue that Venus is worth saving because it’s located within the Solar System’s habitable zone, that special place where water could exist in a liquid state on the surface. But we’re pretty sure it doesn’t have any liquid water. Venus may have been better in the past, clearly it started hanging out with wrong crowd, taking a bad turn down a dark road leading it to its current state of disrepair.

Could Venus have been better in the past? And how did it go so wrong? In many ways, Venus is a twin of the Earth. It’s almost the same size and mass as the Earth, and it’s made up of roughly the same elements. And if you stood on the surface of Venus, in the brief moments before you evacuated your bowels and died horribly, you’d notice the gravity feels pretty similar.

In the ancient past, the Sun was dimmer and cooler than it is now. Cool enough that Venus was much more similar to Earth with rivers, lakes and oceans. NASA’s Pioneer spacecraft probed beneath the planet’s thick clouds and revealed that there was once liquid water on the surface of Venus. And with liquid water, there could have been life on the surface and in those oceans.

Here’s where Venus went wrong. It’s about a third closer to the Sun than Earth, and gets roughly double the solar radiation. The Sun has been slowly heating up over the millions and billions of years. At some point, the planet reached a tipping point, where the water on the surface of Venus completely evaporated into the atmosphere.

False color radar topographical map of Venus provided by Magellan. Credit: Magellan Team/JPL/NASA
False color radar topographical map of Venus provided by Magellan. Credit: Magellan Team/JPL/NASA

Water vapor is a powerful greenhouse gas, and this only increased the global temperature, creating a runaway greenhouse effect on Venus. The ultraviolet light from the Sun split apart the water vapor into oxygen and hydrogen. The hydrogen was light enough to escape the atmosphere of Venus into space, while the oxygen recombined with carbon to form the thick carbon dioxide atmosphere we see today. Without that hydrogen, Venus’ water is never coming back.

Are you worried about our changing climate doing that here? Don’t panic. The amount of carbon dioxide released into the atmosphere of Venus is incomprehensible. According to the IPCC, the folks studying global warming, human activities have no chance of unleashing runaway global warming. We’ll just have the regular old, really awful global warming. So, it’s okay to panic a bit, but do it in the productive way that results in your driving your car less.

The Sun is still slowly heating up. And in a billion years or so, temperatures here will get hot enough to boil the oceans away. And then, Earth and Venus will be twins again and then we can push them both into the Sun.

I know, I said the words “climate change”. Feel free to have an argument in the comments below, but play nice and bring science.

MAVEN Spacecraft’s First Look at Mars Hints at Promising Results

Three views of an escaping atmosphere, obtained by MAVEN’s Imaging Ultraviolet Spectrograph. By observing all of the products of water and carbon dioxide breakdown, MAVEN's remote sensing team can characterize the processes that drive atmospheric loss on Mars. Image Credit: University of Colorado/NASA

It’s been less than a month since NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft slipped into orbit. But it’s already provided mission scientists their first look at Mars’ tenuous atmosphere.

“Everything is performing well so far,” said Bruce Jakosky, the mission’s principle investigator, in a news release. “All the instruments are showing data quality that is better than anticipated at this early stage of the mission. The spacecraft is performing beautifully. It’s turning out to be an easy and straightforward spacecraft to fly, at least so far. It really looks as if we’re headed for an exciting science mission.”

Data collected by MAVEN will answer a longstanding puzzle among planetary scientists. There’s ample evidence that early in the Red Planet’s history it had a much denser atmosphere. Rain fell from the sky and water carved its surface. But then the atmosphere vanished, and scientists are unsure why.

One leading theory is that the gas escaped to space, stripped away by the solar wind rushing past. (Click here to see a cool animation of that process.) Here on Earth, our magnetosphere helps protect our atmosphere from the solar wind. But once Mars lost its own magnetosphere, billions of years ago, its atmosphere became vulnerable.

MAVEN’s spectrometers will attempt to determine if hydrogen atoms, torn from water molecules by ultraviolet sunlight, are escaping to space and at what rate. Already, the spacecraft has observed the edges of the Martian atmosphere using its Imaging Ultraviolet Spectrograph (IUVS) camera, which is sensitive to the sunlight reflected by the atoms.

“With these observations, MAVEN’s IUVS has obtained the most complete picture of the extended Martian upper atmosphere ever made,” said team member Mike Chaffin from Colorado University at Boulder.

So far scientists have used IUVS to create a map of Mars’ ozone. “With these maps we have the kind of complete and simultaneous coverage of Mars that is usually only possible for Earth,” said team member Justin Deighan, also from CU-Boulder.

There will be about two weeks of additional instrument calibration and testing before MAVEN starts its primary science mission in early to mid-November. It will then likely take a few additional months to build up enough measurements to have a clear sense of what’s going on. But the initial results are promising.

MAVEN Arrives at Mars! Parks Safely in Orbit

The control room at Lockheed Martin shortly before MAVEN successfully entered Mars orbit tonight September 21, 2014. Credit: NASA-TV

138 million miles and 10 months journey from planet Earth, MAVEN moved into its new home around the planet Mars this evening. Flight controllers at Lockheed Martin Space Systems in Littleton, Colorado anxiously monitored the spacecraft’s progress as onboard computers successfully eased the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft into Mars orbit at 10:24 p.m. Eastern Daylight Time. 

Shortly before orbital insertion, six small thrusters were fired to steady the spacecraft so it would enter orbit in the correct orientation. This was followed by a 33-minute burn to slow it down enough for Mars’ gravity to capture the craft into an elliptical orbit with a period of 35 hours. Because it takes radio signals traveling at the speed of light 12 minutes to cross the gap between Mars and Earth, the entire orbital sequence was executed by onboard computers. There’s no chance to change course or make corrections, so the software has to work flawlessly. It did. The burn, as they said was “nominal”, science-speak for came off without a hitch.

Simulation of MAVEN in Martian orbit. Credit: NASA
Simulation of MAVEN in orbit around Mars. The craft’s unique aerodynamically curved solar panels allow it to dive more deeply into the Martian atmosphere. Credit: NASA

“This was a very big day for MAVEN,” said David Mitchell, MAVEN project manager from NASA’s Goddard Space Flight Center, Greenbelt, Maryland. “We’re very excited to join the constellation of spacecraft in orbit at Mars and on the surface of the Red Planet. Congratulations to the team for a job well done today.”

Over the next six weeks, controllers will test MAVEN’s instruments and shape its orbit into a long ellipse with a period of 4.5 hours and a low point of just 93 miles (150 km), close enough to get a taste of the planet’s upper atmosphere. MAVEN’s one-Earth-year long primary mission will study the composition and structure of Mars’ atmosphere and how it’s affected by the sun and solar wind. At least 2,000 Astronomers want to determine how the planet evolved from a more temperate climate to the current dry, frigid desert.

Evidence for ancient water flows on Mars - a delta in Eberswalde Crater. Credit: NASA
Evidence for ancient water flows on Mars – a delta in Eberswalde Crater. Credit: NASA

Vast quantities of water once flowed over the dusty red rocks of Mars as evidenced by ancient riverbeds, outflow channels carved by powerful floods, and rocks rounded by the action of water. For liquid water to flow on its surface without vaporizing straight into space, the planet must have had a much denser atmosphere at one time.

Mars may have been much more like Earth is today 3-4 billion years ago with a thicker atmosphere and water flowing across its surface. Today, it's evolved into dry, cold planet with an atmosphere as thin as Scrooge's gruel. Credit: NASA
Three to four billion years ago, Mars may have been much more like Earth with a thicker atmosphere and water flowing across its surface (left). Over time,  it evolved into a dry, cold planet with an atmosphere too thin to support liquid water. Credit: NASA

Mars’ atmospheric pressure is now less than 1% that of Earth’s. As for the water, what’s left today appears locked up as ice in the polar caps and subsurface ice. So where did it go all the air go? Not into making rocks apparently. On Earth, much of the carbon dioxide from volcanic outgassing in the planet’s youth dissolved in water and combined with rocks to form carbon-bearing rocks called carbonates. So far, carbonates appear to be rare on Mars. Little has been seen from orbit and in situ with the rovers.

Illustration of electrons and protons in the solar wind slamming into and ionizing atoms in Mars upper atmosphere. Once ionized, the atoms may be carried away by the wind. Credit: NASA
Illustration of electrons and protons in the solar wind slamming into and ionizing atoms in Mars upper atmosphere. Once ionized, the atoms may be carried away by the wind. Credit: NASA

During the year-long mission, MAVEN will dip in and out of the atmosphere some 2,000 times or more to measure what and how much Mars is losing to space. Without the protection of a global magnetic field like the Earth’s,  it’s thought that the solar wind eats away at the Martian atmosphere by ionizing (knocking off electrons) its atoms and molecules. Once ionized, the atoms swirl up the magnetic field embedded in the wind and are carried away from the planet.

MAVEN’s suite of instruments will provide the measurements essential to understanding the evolution of the Martian atmosphere. (Courtesy LASP/MAVEN)
MAVEN’s suite of instruments will provide the measurements essential to understanding the evolution of the Martian atmosphere. Courtesy LASP/MAVEN

Scientists will coordinate with the Curiosity rover, which can determine the atmospheric makeup at ground level. Although MAVEN won’t be taking pictures, its three packages of instruments will be working daily to fill gaps in the story of how Mars became the Red Planet and we the Blue.

For more on the ongoing progress of MAVEN later tonight and tomorrow, stop by NASA TV online. You can also stay in touch by following the hashtags #MAVEN and #JourneytoMars on social media channels including Twitter, Instagram and Facebook. Twitter updates will be posted throughout on the agency’s official accounts @NASA, @MAVEN2Mars and @NASASocial.

Timelapse: Sprites, Gravity Waves and Airglow

Sprite with Airglow and Gravity Waves over South Dakota. Credit and copyright: Randy Halverson.

Look! Fast! Sprite lightning occurs only at high altitudes above thunderstorms, only last for a thousandth of a second and emit light in the red portion of the visible spectrum, so they are really difficult to see. But one of our favorite astrophotographers and timelapse artists, Randy Halverson captured sprites during a recent thunderstorm in South Dakota. But wait, there’s more!

In his timelapse video, above, you’ll also see some faint aurora as well as green airglow being rippled by gravity waves.

See some imagery from the storm, below:

More sprites with airglow and gravity waves over South Dakota on August 20, 2014. Credit and copyright: Randy Halverson.
More sprites with airglow and gravity waves over South Dakota on August 20, 2014. Credit and copyright: Randy Halverson.

See more images and information about Randy’s fun night of observing these phenomena on his website, dakotalapse.

Timelapse: Watch Noctilucent Clouds Cover the Entire Sky

Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand

This year, the noctilucent cloud season has been especially eventful, and this new timelapse from Swedish astrophotographer Göran Strand shows these “night-shining” clouds covering the entire sky over the course of 2 hours.

“On the 27th of July 2014 I saw some of the most beautiful Noctilucent Clouds I’ve ever seen,” Göran said via email. “They emerged shortly after sunset and after a while they covered the entire sky.”

In the movie you can see an all-sky timelapse view that shows how these clouds changed during the evening.

See some gorgeous still photos from that night, below:

Noctilucent clouds are wispy, glowing tendrils of high-altitude ice crystals that shine long after the Sun has set. They appear in upper latitudes only and form about 83 km (51 miles) up in the atmosphere. The icy clouds are illuminated by the Sun when it is just below the horizon, giving the clouds their “night-shining” properties.

Also called polar mesospheric clouds, these are the highest cloud formations in the atmosphere. They’ve been associated with rocket launches and space shuttle re-entries, and another theory is that they might also be associated with meteor activity.

Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand.
Noctilucent clouds over Sweden on July 27, 2014. Credit and copyright: Göran Strand.

See more of Goran’s work at his website, or follow him on Twitter and Facebook.

Facebook:
Twitter: http://twitter.com/Astrofotografen

Cool Infographic Compares the Chemistry of Planetary Atmospheres

"The Chemistry of the Solar System" by Compound Interest's Andy Brunning

Here on Earth we enjoy the nitrogen-oxygen atmosphere we’ve all come to know and love with each of the approximately 24,000 breaths we take each day (not to mention the surprisingly comfortable 14.7 pounds per square inch of pressure it exerts on our bodies every moment.) But every breath we take would be impossible (or at least quickly prove to be deadly) on any of the other planets in our Solar System due to their specific compositions. The infographic above, created by UK chemistry teacher Andy Brunning for his blog Compound Interest, breaks down — graphically, that is; not chemically — the makeup of atmospheres for each of the planets. Very cool!

In addition to the main elements found in each planet’s atmosphere, Andy includes brief notes of some of the conditions present.

“Practically every other planet in our solar system can be considered to have an atmosphere, apart from perhaps the extremely thin, transient atmosphere of Mercury, with the compositions varying from planet to planet. Different conditions on different planets can also give rise to particular effects.”

– Andy Brunning, Compound Interest

And if you’re thinking “hey wait, what about Pluto?” don’t worry — Andy has included a sort of postscript graphic that breaks down Pluto’s on-again, off-again atmosphere as well. See this and more descriptions of the atmospheres of the planets on the Compound Interest blog here.

Source: Compound Interest on Twitter

Heavy-Lift Rocket Launch Seen from Space

Ariane 5 launch on Feb. 6, 2013 captured on camera by NASA astronaut Rick Mastracchio

We all know what a big rocket launch looks like from the ground, but this is what it looks like from above the ground — 260 miles above the ground! The photo above was captured from the Space Station earlier today by NASA astronaut Rick Mastracchio, and it shows the contrail from a heavy-lift Ariane 5 that had just launched from ESA’s spaceport on the French Guiana coast: flight VA217, Arianespace’s milestone 250th launch carrying the ABS-2 and Athena-Fidus satellites into orbit.

Rick shared his view on Twitter with his nearly 39,000 followers, and now less than an hour later, we’re sharing it here. (Isn’t technology wonderful?)

For a more “natural” look, here it is reversed:

Rick Mastracchio's photo of the Ariane 5 launch, rotated 180 degrees.
Rick Mastracchio’s photo of the Ariane 5 launch, rotated 180 degrees.

The ISS was in the process of passing over Costa Rica when the image was taken. The rocket launched from Kourou, French Guiana — about 2,175 miles (3,500 km) away. What a view!

For this and more great images from orbit follow Rick on Twitter @AstroRM.

Watch a video of the VA217 launch below:

The 250th launch performed by Arianespace lifted off from ESA’s spaceport in French Guiana, delivering a dual-satellite payload into geostationary transfer orbit: ABS-2 for global satellite operator ABS, and Athena-Fidus for the defense/homeland security needs of France and Italy. The flight lasted just over 32 minutes. (Source)

Kepler Finds an Earth-Sized “Gas Giant”

Artist's impression of KOI-xxx, fjkdshfkdsajhkfdkfd

Gas planets aren’t always bloated, monstrous worlds the size of Jupiter or Saturn (or larger) they can also apparently be just barely bigger than Earth. This was the discovery announced earlier today during the 223rd meeting of the American Astronomical Society in Washington, DC, when findings regarding the gassy (but surprisingly small) exoplanet KOI-314c were presented.

“This planet might have the same mass as Earth, but it is certainly not Earth-like,” said David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA), lead author of the discovery. “It proves that there is no clear dividing line between rocky worlds like Earth and fluffier planets like water worlds or gas giants.”

Discovered by the Kepler space telescope — ironically, during a hunt for exomoons — KOI-314c was found transiting a red dwarf star only 200 light-years away — “a stone’s throw by Kepler’s standards,” according to Kipping. (Kepler’s observation depth is about 3000 light-years.)

Relative size comparison of KOI-314c and Earth; both have similar mass. (J. Major)
Relative size comparison of KOI-314c and Earth; both have similar mass. (J. Major)

Kipping used a technique called transit timing variations (TTV) to study two of three exoplanets found orbiting KOI-314. Both are about 60% larger than Earth in diameter but their respective masses are very different. KOI-314b is a dense, rocky world four times the mass of Earth, while KOI-314c’s lighter, Earthlike mass indicates a planet with a thick “puffy” atmosphere… similar to what’s found on Neptune or Uranus.

Unlike those chilly worlds, though, this newfound exoplanet turns up the heat. Orbiting its star every 23 days, temperatures on KOI-314c reach 220ºF (104ºC)… too hot for water to exist in liquid form and thus too hot for life as we know it.

In fact Kipping’s team found KOI-314c to only be 30 percent denser than water, suggesting that it has a “significant atmosphere hundreds of miles thick,” likely composed of hydrogen and helium.

It’s thought that KOI-314c may have originally been a “mini-Neptune” gas planet and has since lost some of its atmosphere, boiled off by the star’s intense radiation.

Not only is KOI-314c the lightest exoplanet to have both its mass and diameter measured but it’s also a testament to the success and sensitivity of the relatively new TTV method, which is particularly useful in multiple-planet systems where the tiniest gravitational wobbles reveal the presence and details of neighboring bodies.

(Watch the latest Kepler Orrery video here)

“We are bringing transit timing variations to maturity,” Kipping said. He added during the closing remarks of his presentation at AAS223: “It’s actually recycling the way Neptune was discovered by watching Uranus’ wobbles 150 years ago. I think it’s a method you’ll be hearing more about. We may be able to detect even the first Earth 2.0 Earth-mass/Earth-radius using this technique in the future.”

Source: Harvard Smithsonian CfA press release