Fifth Moon Found Around Pluto

This just in! Astronomers working with the Hubble Space Telescope have spotted a new moon around distant Pluto, bringing the known count up to 5. The image above was released by NASA just minutes ago, showing the Pluto system with its newest member, P5.

This news comes just a couple of weeks shy of the one-year anniversary of the announcement of Pluto’s 4th known moon, still currently named “P4”.

The news was shared this morning by an undoubtedly excited Alan Stern of the Southwest Research Institute (SwRI) on Twitter.

Astronomers estimate P5 to be between 6 and 15 miles (9.6 to 24 km) in diameter. It orbits Pluto in the same plane as the other moons — Charon, Nix, Hydra and P4.

“The moons form a series of neatly nested orbits, a bit like Russian dolls,” said team lead Mark Showalter of the SETI Institute.

A mini-abstract of an upcoming paper lists image sets acquired on 5 separate occasions in June and July. According to the abstract, P5 is 4% as bright as Nix and 50% as bright as P4.

The satellite’s mean magnitude is V = 27.0 +/- 0.3, making it 4 percent as bright as Pluto II (Nix) and half as bright as S/2011 (134340) 1. The diameter depends on the assumed geometric albedo: 10 km if p_v = 0.35, or 25 km if p_v =0.04. The motion is consistent with a body traveling on a near-circular orbit coplanar with the other satellites. The inferred mean motion is 17.8 +/- 0.1 degrees per day (P = 20.2 +/- 0.1 days), and the projected radial distance from Pluto is 42000 +/- 2000 km, placing P5 interior to Pluto II (Nix) and close to the 1:3 mean motion resonance with Pluto I (Charon).

The new detection will help scientists navigate NASA’s New Horizons spacecraft through the Pluto system in 2015, when it makes an historic and long-awaited high-speed flyby of the distant world.

See the news release from NASA here.

(H/T to Ray Sanders at

Top image: NASA, ESA and M. Showalter (SETI Institute)

Gallery: Discovery Leaves Kennedy Space Center for the Final Time

Discovery leaves Kennedy Space Center for the final time. Credit: Mike Deep.


It’s the end of an era. For 29 years space shuttle Discovery has been leaving Kennedy Space Center on solid rocket boosters and her own engines. Now she’s left for the final time on top of a modified Boeing 747, known as the Shuttle Carrier Aircraft, to head to her new, final home at the Smithsonian National Air & Space Museum in Washington D.C. Discovery departed Florida’s Kennedy Space Center at daybreak on April 17, 2012. The duo took one last flyover flight over the beaches of Cape Canaveral. A similar flyover is planned over the nation’s capital when they arrive later today. We have images of the event from Universe Today photographer, as well as former shuttle technician Jen Scheer (@flyingjenny) — thanks to Jen for sharing her images of Discovery’s departure. See more below from Mike and Jen (you can also visit Jen’s Flickr page). The video below was taken by Andy Scheer, another shuttle technician.

Discovery is the first of the three remaining space shuttles to head to a museum. The shuttle prototype, Enterprise that is currently at the Air & Space museum will go to New York City’s Intrepid Museum. Endeavour will go to Los Angeles this fall, while Atlantis will remain at KSC.

Orbiter Discovery is carried on the Shuttle Carrier Aircraft up and down the beaches of Brevard County as a farewell on her way to Washington D.C. and her new home at the National Air & Space Museum. Credit: Jen Scheer.
Discovery atop the Shuttle Carrier Aircraft heads down the runway at KSC. Credit: Mike Deep.
Orbiter Discovery is carried on the Shuttle Carrier Aircraft up and down the beaches of Brevard County as a farewell on her way to Washington D.C. and her new home at the National Air & Space Museum. Credit: Jen Scheer.

Takeoff for Discovery. Credit: Mike Deep.

Banking gently, Orbiter Discovery is carried on the Shuttle Carrier Aircraft up and down the beaches of Brevard County as a farewell on her way to Washington D.C. and her new home at the National Air & Space Museum. Credit: Jen Scheer.

A T-38 aircraft escorts Discovery atop the Shuttle Carrier Aircraft. Credit: Jen Scheer.

This video was taken on the beach in Cape Canaveral:

Discovery leaving Florida for the final time. Credit: Mike Deep.

Who Discovered Mercury?

Mercury's limb. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Mercury is one of the 5 planets visible with the unaided eye. Even thousands of years ago, ancient astronomers knew that the 5 wanderers were different from the other stars in the sky. The 5 planets visible with the unaided eye are Mercury, Venus, Mars, Jupiter and Saturn. They gave them distinct names, and charted their positions with incredible accuracy. It’s impossible to say “when was Mercury discovered”, since that would have been before recorded history.

But when did astronomers realize that Mercury was a planet? That happened with Copernicus developed his model of a Sun-centered Solar System, published in 1543. With the Sun at the center of the Solar System, and not the Earth, it meant that both the Earth and Mercury were planets. This discovery was confirmed when Galileo first turned his telescope on the planets and realized they matched predictions made by Copernicus. Unfortunately, Galileo’s telescope wasn’t powerful enough to reveal a disk for Mercury, but it did show how Venus went through phases like the Moon.

This model was backed up by Galileo, who pointed his first rudimentary telescope at Mercury in the 17th century. Unfortunately his telescope wasn’t powerful enough to see Mercury go through phases like he saw with Venus.

Because it’s so small and close to the Sun, Mercury was difficult to observe with ground-based telescopes. More powerful telescopes only revealed a small grey disk; they didn’t have the resolution to display features on the planet’s surface, like craters or lava fields.

It wasn’t until the early 1960s when radio astronomers started bouncing signals off the surface of Mercury that more information was finally known about the planet. These signals revealed that Mercury’s day length is about 59 days. Even more detailed observations have been made with the Arecibo telescope, mapping surface features down to a resolution of 5 km.

The most detailed observations of Mercury have come from the exploration from spacecraft sent from Earth. NASA’s Mariner 10 spacecraft swept past Mercury in 1974, capturing images from an altitude of just 327 km. It eventually mapped about half of the planet in unprecedented detail, revealing that the planet looked very similar to the Earth’s moon, with many impact craters and ancient lava fields.

If you’re wondering who discovered the element mercury, nobody knows that either. The element has been known for thousands of years, and was used by the ancient Chinese. Liquid mercury was found in Egyptian tombs closed up almost 4,000 years ago.

We have written many articles about Mercury for Universe Today. Here’s an article about new mysteries unveiled on Mercury, and the possibility that Mercury could cause an interplanetary smash-up.

Want more information on Mercury? Here’s a link to NASA’s Solar System Exploration Guide, and here’s a link to NASA’s MESSENGER Mission Page.

We have also recorded a whole episode of Astronomy Cast that’s just about planet Mercury. Listen to it here, Episode 49: Mercury.

NASA Cosmic Distance Scales
NASA Solar System Exploration: Mariner 10

New Comet Discovered by Amateur Astronomer

Image of Comet C/2012 C2 (Bruenjes) made from ten 60 sec. exposures on Feb. 11, 2012. (Fred Bruenjes)


“Friday, February 10th 2012 just felt like the perfect night for a comet to be discovered by an amateur astronomer,” writes Fred Bruenjes on his astronomy blog. And, this past Friday night, that’s exactly what Fred did.

Here’s how he did it:

Using custom-written software to operate a 14″ Meade LX200GPS telescope in his self-built observatory in Warrensburg, Missouri, Fred set his system up to capture images of the sky on that cold evening, not allowing himself to be chased inside by the low temperatures or the bright, rising moon. After some technical difficulties with his dSLR, Fred managed to acquire some quality images. While making a cursory look through the blink data, Fred was surprised to spot a faint burry object visible moving across three frames. A check of online databases of known objects brought up no positive hits — this was something that hadn’t been seen before.

Raw-color discovery image. (Fred Bruenjes)

Fred describes the “eureka” moment on his blog:

A check of known objects in the region had a lot of results in the area, but all were moving eastward while my fuzzy was moving westward. Rocks don’t make U-turns. This was really getting exciting. I had Jen, my better half, an accomplished astro imager, take a look at the images and before I could point out the faint smudge she exclaimed “That’s a comet!”

Still, Fred notes, “it wasn’t a slam-dunk.” The images were faint and there could have been other causes of blurry spots in digital images. But a check of the raw color data revealed a greenish coloration to the object’s glow, which is indicative of cyanogen and carbon emission — typical hallmarks of comets. “Very encouraging,” Fred added.

Another night’s observation was needed. If it was a comet, it would appear again along its expected trajectory. Of course, with an unidentified comet there would be no known orbit, so Fred had to manually extrapolate its position. When he trained his telescope onto his calculated coordinates the following evening and began taking images, there it was… the same faint, fuzzy green blur from the previous night, slowly appearing in the darkening sky right where it should be.

“Oh. Wow. It was dead nuts at where it was supposed to be,” Fred writes. “Wow. This thing is for real! It’s at about this time that it begins to sink in that a lifelong quest has just been fulfilled. I just crossed another thing off the bucket list!”

Fred spent the next hour gathering images to send in to the IAU’s Minor Planet Center, in the hopes of having the object cataloged so that others could locate and observe it. He didn’t have to wait long; within five minutes the object was listed on the Near-Earth Object Confirmation Page, and dubbed C/2012 C2 (Bruenjes), in honor of its discoverer.

Now that’s just got to feel good.

Comet Bruenjes is an NEO currently about 0.555 AU away from Earth. Its exact size and orbital period isn’t known, and it may even be a returning comet or piece from a larger one… the official report isn’t out yet. It appears to have a fairly inclined orbit relative to the ecliptic, based on the current diagram created by JPL’s Small-Body Database.

Currently plotted orbit of C/2012 C2 (Bruenjes) (NASA/JPL)

The comet’s total magnitude is 16.6, so it is dim and not visible to the naked eye. Fred told Universe Today in an email: “it’s in the constellation Aries, about six degrees north of Jupiter. Just after sunset in the Northern hemisphere it’s high in the southwest, nearly overhead.”

Stay tuned for more updated information on this newly-discovered member of our solar system. And congratulations to Fred Bruenjes, comet-hunter extraordinaire!

Read Fred’s full story on his astronomy site here.

Images © 2012 Manfred Bruenjes. All rights reserved. Used with permission.


Finding Phobos: Discovery of a Martian Moon

Phobos, one of the two natural satellites of Mars silhouetted against the Martian surface. Credit: ISRO
Mars Express images of Phobos from January 9, 2011 flyby

If someone were to ask you when fear was first discovered, you could tell them August 11, 1877. That’s when, 134 years ago today, Asaph Hall identified Phobos, the larger of Mars’ two moons. But even though it’s named after the Greek god of fear, there’s nothing to be afraid of…

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Shuttle Discovery Rolls Back to Vehicle Assembly Building

Space shuttle Discovery waits to roll back from Launch Pad 39A to the Vehicle Assembly Building (VAB) at NASA's Kennedy Space Center in Florida in the early morning hours of Dec 21, 2010, with the beginning of the total lunar eclipse clearly in view. Credit: NASA/Kim Shiflett


Overnight, space shuttle discovery left launch pad 39A and was rolled back to the Vehicle Assembly Building. There, engineers can use digital X-ray equipment to look at the external fuel tank and attempt to determine what caused the tops of two, 21-foot-long support beams, called stringers, on the outside of the intertank to crack during fueling on Nov. 5. Additionally, foam will be reapplied where 89 sensors were installed on the tank’s aluminum skin for an instrumented tanking test on Dec. 17. The sensors were used to measure changes in the tank last week as super-cold propellants were pumped in and drained out.

This rollback of Discovery was her sixth, and the 20th rollback in the space shuttle program. If everything checks out in the VAB, Discovery is slated to return to the launchpad around January 14, 2011. Discovery’s next launch opportunity is no earlier than Feb. 3.

Engineers also hope to verify their hypothesis that the stinger cracks occurred during cryogenic fueling because of unusual “stresses” on the support beams that took place during the tank’s construction.

And we’ve said it before: never say “last” when it comes to the space shuttle! Discovery’s “last” rollout to the pad was three months ago. And as Peter King from CBS news said on Twitter, not only do we get another rollout, we also get another “last” night launch if the date of February 3 holds. The original “last night shuttle launch” was the February 2010 launch of Endeavour, which I attended, but then the subsequent launch of Discovery in April ended up being a night launch because of delays. Looks likely we’ll have at least one more night launch that turns night into day at KSC.

Soyuz Launches; Discovery’s Final Payload Delivered to Launch Pad

In the left of this image the payload canister sits attached to the Rotating Service Structure (RSS) waiting to have STS-133's payload removed. Photo Credit: Universe Today/Jason Rhian


October 7 was a busy day in spaceflight, as a Soyuz launched 2 cosmonauts and 1 astronaut to the International Space Station, and for the last time the payload canister for the space shuttle Discovery made its way to Launch Complex 39A (LC39A) at NASA’s Kennedy Space Center (KSC) in Florida. Crews are now preparing to install the payload into Discovery’s cargo bay on Monday morning, which includes the first humanoid robot to fly into space Robonaut-2 or “R2.”

See below for a video of the Soyuz launch.

Alexander Kaleri, Oleg Skripochka and Scott Kelly are now on their way to join three other crew members aboard the ISS station after a two-day trip on the Soyuz.

For the final flight of Discovery, STS-133, the another payload is the reconfigured Leonardo Multi-Purpose Logistics Module (MPLM) now dubbed the Permanent Multipurpose Module. The mission will also carry the Express Logistics Carrier 4 and much-needed spare parts to the International Space Station (ISS).

The mission is slated to launch no-earlier-than Nov.1 at 4:40 p.m. EDT.

A large white canister is hoisted up and the payload that is sealed inside will be removed. From there the canister is taken away, the Rotating Service Structure (RSS) will swing over the space shuttle and then be loaded into the shuttle’s cargo bay. The entire process takes a little over a week.

STS-133 will mark the final flight of the space shuttle Discovery. Photo Credit: Universe Today/Alan Walters

The crew for STS-133 consists of Commander Steve Lindsey, Pilot Eric Boe and Mission Specialists Nicole Stott, Alvin Drew, Tim Kopra and Michael Barratt.

The crew of STS-133. from left to right, Alvin Drew, Nicole Stott, Eric Boe, Steve Lindsey, Micheal barratt and Tim Kopra. Image Credit: NASA

The canisters that deliver the payload out to the launch pad have been used since the shuttle program’s inception. However, that does not mean that they are destined to go to the Smithsonian or some other world-famous museum. In fact there is no real clear destination for any of these pieces of hardware. As NASA no longer has a clear path forward it is not known whether-or-not the canisters will be used in some future, as-yet-unnamed program.

“They’re pretty old critters, they’ve been with us since the beginning of the shuttle program,” said Scott Higginbotham NASA’s mission manager in charge of payloads. “They’ve delivered all the payloads either to the Orbiter Processing Facility (OPF) for horizontal installation or out here to the pad for vertical installation.”

The payload canister is loaded onto the RSS in preparation for loading into Space Shuttle Discovery for STS-133. Image is an HDR composite from five images. Credit: Alan Walters ( for Universe Today.

The final rollover for Discovery – SpacePod 2010.09.13

While rollover actually happened on September 9th, I thought it may be fitting to post our rollover/tribute video to Discovery. Unlike the first last mission for Atlantis (as opposed to the last, last mission), there is no hope for an additional flight of Discovery. This is really, really the last time Discovery will roll from the orbital processing facility to the VAB. You’re watching the beginning of the end here.

Stunning Look at ISS and Docked Disovery — From the Ground!

ISS with shuttle Discovery docked on April 8, 2010. Credit: Ted Judah


This has to be one of the clearest close-up shots of the International Space Station ever taken from the ground! Plus it has the added bonus of having space shuttle Discovery docked to the station. Ted Judah, who lives in northern California captured this image — one of 150 he took during the an ISS pass over his observatory during the recent STS-131 mission. Here’s Ted’s description:

The ISS came into the morning light over the Pacific Ocean just off the coast of northern California and was tracking north-east as it passed directly over my sea-level observatory. I was lucky there was no fog. I have a Canon 30D SLR and Celestron 11″ Schmidt-Cassagrain on an equatorial mount. I track manually and use my precisely-aligned finderscope to aim – when the ISS is in the crosshairs I shoot like crazy. Of the 150 shots I took, less than half have the ISS in frame.

Ted told me he was “stoked” to get such a clear image. Who wouldn’t be?? Nice work, Ted!

Ted is not new to trying to capture the ISS. He won one of “Phil’s Picks” (Bad Astronomer Phil Plait) in Celestron’s “Capture the Universe” contest with another image of the ISS.

Also, Ted has contributed a couple of podcasts to 365 Days of Astronomy, and one of my all-time favorite podcasts is Ted’s description of how he and his family built an observatory out on his father-in-law’s farm.

Here’s another shot Ted took during the same pass:

The ISS and shuttle Discovery during the STS-131 mission. Credit: Ted Judah

Thanks Ted, for sharing your wonderful images!

Double Spaceship Sighting Alert!

The ISS, as seen from space shuttle Endeavour on the STS-130 mission. Credit: NASA

Since this perhaps the fourth-to-the-last space shuttle flight, right now is a great opportunity to see the marvelous sights of International Space Station and space shuttle Discovery flying close in tandem. Depending on where you live, Tuesday evening or early Wednesday morning should provide a wonderful opportunity to see the two as the shuttle prepares to dock at 7:44 GMT (3:44 a.m EDT) on April 7, 2010.

Before docking, the two spacecraft will be seen as separate but closely-spaced points of light. The ISS is bigger, so will appear as the brighter object leading the smaller Discovery as they move across the sky. After docking, the ISS will be brighter yet with the additional surface area provided by the docked shuttle. Of course, your viewing ability will depend on cloud cover.

To find out if you’ll be able to see spaceships in your area, there are a few different sites to check out:
Continue reading “Double Spaceship Sighting Alert!”