Elizabeth Howell, Author at Universe Today

December 16, 2014December 23, 2015 by Elizabeth Howell

Name That Crater On Mercury! MESSENGER Team Opens Public Contest

The crater Scarlatti (at center) shines clearly in this image of Mercury taken by the MESSENGER spacecraft. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Here’s your rare chance to leave a lasting mark on a piece of the Solar System. The team behind the MESSENGER spacecraft — that machine orbiting Mercury since 2011 — is asking the public to help them name craters on the planet, in an open contest.

Fifteen finalists will be forwarded to the official arbitrator of astronomical names on Earth, the International Astronomical Union, which will pick five names in time for the end of the MESSENGER mission this spring.

“This brave little craft, not much bigger than a Volkswagen Beetle, has travelled more than 8 billion miles [12.8 billion kilometers] since 2004—getting to the planet and then in orbit,” stated Julie Edmonds of the Carnegie Institution for Science, who leads the MESSENGER education and public outreach team.

A crater on Mercury at the edge of the larger Oskison crater located in the plains north of Caloris basin. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

“We would like to draw international attention to the achievements of the mission and the guiding engineers and scientists on Earth who have made the MESSENGER mission so outstandingly successful.”

Here are some guidelines to increase your chances of success:
– Make sure the name does not have significance politically, religiously or for the military;
– Focus on names of writers, artists and composers and research them thoroughly, as you will be expected to provide a justification;
– Don’t pick a name that has been used elsewhere in the Solar System.

Mercury's southern polar region as seen from MESSENGER. (Credit: NASA/Johns Hopkins UniversityApplied Physics Laboratory/Carnegie Institution of Washington). — Mercury’s southern polar region as seen from MESSENGER. (Credit: NASA/Johns Hopkins UniversityApplied Physics Laboratory/Carnegie Institution of Washington).

Some additional hints come from the official contest website, which adds that the competition is open to everyone except MESSENGER’s education and public outreach team and that entries close Jan. 15.

Impact craters are named in honor of people who have made outstanding or fundamental contributions to the Arts and Humanities (visual artists, writers, poets, dancers, architects, musicians, composers and so on). The person must have been recognized as an art-historically significant figure for more than 50 years and must have been dead for at least three years. We are particularly interested in submissions that honor people from nations and cultural groups that are under-represented amongst the currently-named craters.

This isn’t the first planet with recent open invitations for the public to name craters. Earlier this year, astronomy education group Uwingu began asking for suggestions to name craters on Mars for maps that will be used by the Mars One team as it plans to land a private crewed mission on the planet in the coming years. Those names, however, will likely not be recognized by the IAU (the official statement is here.)

December 16, 2014December 23, 2015 by Elizabeth Howell

Robotic Moon Lander Concept Raises $942K, Meeting Goal With A Day To Go

Artist's conception of Lunar Mission One's robotic lander touching down on the surface. Credit: Lunar Missions Ltd.

Update, Dec. 18, 8:09 a.m. EST: Lunar Mission One closed its fundraising mission the night before at £672,447 ($1,052,413), short of its stretch goal of £700,000.

With just over a day to go in their crowdfunding campaign, a British group hoping to put a robotic lander on the moon in 2024 reached their fundraising goal of $932,000 (£600,000) overnight.

The money is supposed to move the project into more concrete phases after the founders spent seven years quietly developing their concept, but many of the details about the design and funding have yet to be unveiled.

“We plan to send an unmanned robotic landing module to the South Pole of the Moon – an area unexplored by previous missions,” the mission says on its Kickstarter page. “We’re going to use pioneering technology to drill down to a depth of at least 20m – 10 times deeper than has ever been drilled before – and potentially as deep as 100m.

“By doing this,” the statement adds, “we will access lunar rock dating back up to 4.5 billion years to discover the geological composition of the Moon, the ancient relationship it shares with our planet and the effects of asteroid bombardment. Ultimately, the project will improve scientific understanding of the early Solar System, the formation of our planet and the Moon, and the conditions that initiated life on Earth.”

Artist's conception of a moon drill that could potentially be used by Lunar Mission One's lunar lander. Credit: Lunar Missions Ltd. — Artist’s conception of a moon drill that could potentially be used by Lunar Mission One’s lunar lander. Credit: Lunar Missions Ltd.

“Stretch goals” for the organization include rewards for backers such as an e-commerce program, a massive open online course for educational purposes, a party for backers in London, and being “a leading role” in World Space Week 2015. The additional money, however, will also be used for drilling studies, putting together the science team and making a work plan.

With the money raised, the project now has the ambitious target of getting their lander on the moon by 2024. According to the schedule, the main mission contract should be awarded by 2017, design and development begins by 2018, and the final build commences in 2021.

RAL Space (which assisted with the Philae comet landing and 200 other space missions, according to the page) is serving as a technical advisor to the board. The project chair of Lunar Missions Ltd. (which is responsible for the project) is Ian Taylor, a former United Kingdom government science minister and co-chair of the parliamentary space committee.

As with other private ventures in space such as Mars One, however, Lunar Mission One is dealing with long timelines, a risky goal and a not-certain guarantee of success.

December 15, 2014December 23, 2015 by Elizabeth Howell

Martian Teardrop: Here’s How The Sun Moves Over A Red Planet Year

The Opportunity rover captured this analemma showing the Sun's movements over one Martian year. Images taken every third sol (Martian day) between July, 16, 2006 and June 2, 2008. Credit: NASA/JPL/Cornell/ASU/TAMU

Stand in the same spot every day. Take a picture of the Sun. What happens? Slowly, you see our closest star shifting positions in the sky. That motion over an entire year is called an analemma. The Opportunity rover on Mars even captured one on the Red Planet, which you can see above, and it’s a different shape than what you’ll find on Earth.

An April Astronomy Picture of the Day post (highlighted this weekend on Reddit) explains that Earth’s analemma of the Sun is figure-8-shaped, while that on Mars looks somewhat like a pear (or a teardrop, we think.) The Earth and Mars each have about the same tilt in their orbit — that same tilt that produces the seasons — but the orbit of Mars is more elliptical (oval) than that of Earth.

An analemma of the Sun, taken from Budapest, Hungary over a one year span. (Courtesy of György Soponyai, used with permission).

“When Mars is farther from the Sun, the Sun progresses slowly in the martian sky creating the pointy top of the curve,” the APOD post stated. “When close to the Sun and moving quickly, the apparent solar motion is stretched into the rounded bottom. For several sols some of the frames are missing due to rover operations and dust storms.”

The picture you see at the top of the post was taken every third sol (or Martian day, which is 24 hours and 37 minutes) between July 2006 and June 2008. The landscape surrounding the analemma is from Victoria Crater, where Opportunity was roaming at that time. (The rover is now on the rim of Endeavour Crater, still trucking after nearly 11 full years on the surface.)

In 2006, APOD also published a simulated analemma from Sagan Memorial Station, the landing site of the Sojourner spacecraft and tiny Pathfinder rover. In this case, the simulation showed the Sun’s movements every 30 sols. A Martian year is 668 sols.

You can read more details about analemmae in this past Universe Today post by David Dickinson, which relates the phenomenon to the passage of time.

December 15, 2014December 23, 2015 by Elizabeth Howell

Could Mercury Get A Meteor Shower From Comet Encke?

Artist's concept of the planet Mercury orbiting through a debris trail from Comet Encke that may cause a meteor shower. Credit: NASA's Goddard Space Flight Center

We’re sure going to miss the MESSENGER spacecraft at Mercury when it concludes its mission in 2015, because it keeps bringing us really unexpected news about the Sun’s closest planet. Here’s the latest: Mercury may get a periodic meteor shower when it passes through the debris trail of Comet Encke.

Why do scientists suspect this? It’s not from patiently watching for shooting stars. Instead, they believe the signature of calcium in Mercury’s tenuous atmosphere may be pointing to a pattern.

MESSENGER (which stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging) has been orbiting the planet for three Earth years and sees regular “surges” in calcium abundance on a predictable schedule. The researchers suspect it’s because of bits of dust colliding with Mercury and ricocheting bits of calcium up from the surface.

Mercury also picks up bits of dust from interplanetary debris, but the scientists say it’s not enough to account for the amounts of calcium they see. Extrapolating, the researchers suspect it must occur as the planet passes through debris left behind from a comet or asteroid. There are a small number of such small bodies that do this, and the scientists narrowed it down to Encke.

Illustration of MESSENGER in orbit around Mercury (NASA/JPL/APL)

Computer simulations of the comet’s debris showed a slight difference from what researchers predicted, but they believe it’s because of variations in Mercury’s orbit as it gets tugged by larger planets, particularly Jupiter. Encke itself takes about 3.3 years to do one lap around the Sun, and has been photographed by MESSENGER in the past.

“The possible discovery of a meteor shower at Mercury is really exciting and especially important because the plasma and dust environment around Mercury is relatively unexplored,” stated lead author Rosemary Killen, a planetary scientist at NASA’s Goddard Space Flight Center in Maryland.

MESSENGER, meanwhile, is burning off the last of its fuel to stay in orbit; the final engine maneuver is expected for Jan. 21. Once that’s finished, the spacecraft will slowly spiral down towards the planet for an expected impact in March, ending the mission.

Source: NASA

December 15, 2014December 23, 2015 by Elizabeth Howell

How NASA Filmed Humans Last Leaving The Moon, 42 Years Ago

Still of the Apollo 17 spacecraft leaving the moon on Dec. 14, 1972. Credit: NASA/YouTube (screenshot)

When Apollo 17 lifted off from the moon, a camera captured the movements of the spacecraft — even though nobody was left behind to, say, establish a lunar base. How was that possible? With a camera on the lunar rover that could be controlled — or even programmed — from Earth.

Pretty impressive technology for the takeoff 42 years ago yesterday (Dec. 14) in 1972, although it took three tries to get the technique right.

As the Smithsonian National Air and Space Museum explains in a 2011 blog post, the camera was available on Apollos 15, 16 and 17. The television camera communicated from Earth using a high-gain antenna on the rover, but there was a slight time delay for the radio waves to travel (a couple of seconds) between the Earth and the Moon.

So the engineers suggested moving the rover a certain distance from the lunar module and setting the camera to automatically tilt to show the lunar liftoff when commanded from Earth.

That was the plan, at least. On Apollo 15, the tilt mechanism malfunctioned and the camera never moved upwards, allowing the lunar module to slip out of sight. And while the attempt on Apollo 16 gave a longer view of the lunar module rising up, the astronauts actually parked the rover too close to it, which threw off the calculations and timing of the tilt upwards so it left view just a few moments into the flight.

Ed Fendall was the person doing the controlling. In an oral history for NASA done in 2000, he recalled how complex the procedure was.

Now, the way that worked was this. Harley Weyer, who worked for me, sat down and figured what the trajectory would be and where the lunar rover would be each second as it moved out, and what your settings would go to. That picture you see was taken without looking at it [the liftoff] at all. There was no watching it and doing anything with that picture. As the crew counted down, that’s a [Apollo] 17 picture you see, as [Eugene] Cernan counted down and he knew he had to park in the right place because I was going to kill him, he didn’t — and Gene and I are good friends, he’ll tell you that — I actually sent the first command at liftoff minus three seconds. And each command was scripted, and all I was doing was looking at a clock, sending commands. I was not looking at the television. I really didn’t see it until it was over with and played back. Those were just pre-set commands that were just punched out via time. That’s the way it was followed.

December 12, 2014December 23, 2015 by Elizabeth Howell

New Map Shows ‘Marsquakes’ Shook Wet Valles Marineris Sand, NASA Says

A color mosaic of Candor Chasma (part of Mars' Valles Marineris) based on data from Voyager 1 and Voyager 2. Credit: NASA

Mars today is a planet that appears to be mostly shaped by wind, but that wasn’t always the case. A new map adds information to the hypothesis that “marsquakes” affected at least a part of the planet’s vast canyon, Valles Marineris, while the area contained spring-filled lakes.

When the damp sand got shaken up, it deposited itself in hills. NASA says the new map, based on observations from the Mars Reconnaissance Orbiter (which you can see below), adds credence to the theory that it was water that made these deposits.

“The conditions under which sedimentary deposits in it formed have been an open issue for decades,” NASA wrote in a press release. “Possibilities proposed have included accumulation in lakebeds, volcanic eruptions under glaciers within the canyons, and accumulation of wind-blown sand and dust.”

The map you see below was created by the U.S. Geological Survey, which has more extensive information on the findings at this website. The observations also produced a suite of research in recent years, such as this 2009 paper led by Scott Murchie at the Johns Hopkins University Applied Research Laboratory.

Part of a map of Candor Chasma (part of Mars' Valles Marineris) based on observations from the Mars Reconnaissance Orbiter. Green is knobby terrain, pink is lobate deposits (ridged material) and blue "stair-stepped morphology" of hills and mesas. Credit: U.S. Geological Survey — Part of a map of Candor Chasma (part of Mars’ Valles Marineris) based on observations from the Mars Reconnaissance Orbiter. Green is knobby terrain, pink is lobate deposits (ridged material) and blue “stair-stepped morphology” of hills and mesas. Credit: U.S. Geological Survey

December 12, 2014December 23, 2015 by Elizabeth Howell

Freak Fast Winds Created Titan’s Massive, Mysterious Dunes

Titan's surface is almost completely hidden from view by its thick orange "smog" (NASA/JPL-Caltech/SSI. Composite by J. Major)

Titan is Saturn’s largest moon and is constantly surprising scientists as the Cassini spacecraft probes under its thick atmosphere. Take its dunes, for example, which are huge and pointed the wrong way.

Why are they pointing opposite to the prevailing east-west winds? It happens during two rare wind reversals during a single Saturn year (30 Earth years), investigators suggest.

Investigators repurposed an old NASA wind tunnel to simulate how Titan is at the surface, watching how the wind affects sand grains. (They aren’t sure what kind of sand is on Titan, so they tried 23 different kinds to best simulate what they think it is, which is small hydrocarbon particles that are about 1/3 the density of what you find on Earth.)

After two years of work with the model — not to mention six years of refurbishing the tunnel — the team determined that the wind must blow 50% faster than believed to get the sand moving.

Dunes on Titan seen in Cassini's radar (top) that are similar to Namibian sand dunes on Earth. The features that appear to be clouds in the top picture are actually topographic features. Credit: NASA — Dunes on Titan seen in Cassini’s radar (top) that are similar to Namibian sand dunes on Earth. The features that appear to be clouds in the top picture are actually topographic features. Credit: NASA

“It was surprising that Titan had particles the size of grains of sand—we still don’t understand their source—and that it had winds strong enough to move them,” stated Devon Burr, an associate professor at the University of Tennessee Knoxville’s earth and planetary science department, who led the research. “Before seeing the images, we thought that the winds were likely too light to accomplish this movement.”

The winds reverse when the Sun moves over the equator, affecting Titan’s dense atmosphere. And the effects are powerful indeed, creating dunes that are hundreds of yards (or meters) high and stretch across hundreds of miles (or kilometers).

To accomplish this, the winds would need to blow no slower than 3.2 miles per hour (1.4 meters per second), which sounds slow until you consider how dense Titan’s atmosphere is — about 12 times thicker surface pressure than what you would find on Earth. More information on the research is available in the journal Nature.

Sources: Arizona State University and the University of Tennessee, Knoxville.

December 12, 2014December 23, 2015 by Elizabeth Howell

Dawn Spacecraft’s Dwarf Planet Dance Improves Hubble’s Far-Away View

Vesta seen from the Earth-orbit based Hubble Space Telescope in 2007 (left) and up close with the Dawn spacecraft in 2011. Hubble Credit: NASA, ESA, and L. McFadden (University of Maryland). Dawn Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Photo Combination: Elizabeth Howell

The Hubble Space Telescope is one of the best observatories humanity has. It’s been operating for nearly 25 years in space, is still highly productive, and is a key element to mission planning for NASA as it sends spacecraft out into the Solar System. When the agency was getting ready to send Dawn to Vesta, for example, it took pictures to help with calibration.

Then Dawn got up close to the dwarf planet in 2011 and found a few surprises — liquid water that possibly flowed temporarily on the surface, for example. And as the spacecraft draws near to Ceres for a close encounter next year, it also will be looking for water — in the form of its atmosphere.

That’s following on from research out of the Herschel Space Telescope published earlier this year, showing that Ceres has a thin water vapor atmosphere surrounding the dwarf planet. It could be producing water similarly to how a comet does, through sublimation, but investigators won’t know much until they get close-up.

“Ceres has some sort of mechanism that’s putting out water vapor and causing a thin, temporary atmosphere,” said Keri Bean, a mission operations engineer at the Jet Propulsion Laboratory who works on Dawn, in a Google+ Hangout yesterday (Dec. 11). “I think that we’re going to try to look into this, and we don’t know what else Ceres will have in store for us.”

Ceres as seen from the Earth-based Hubble Space Telescope in 2004 (left) and with the Dawn spacecraft in 2014 as it approached the dwarf planet. Hubble Credit: NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), L. McFadden (University of Maryland, College Park), and M. Mutchler and Z. Levay (STScI). Dawn Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Photo Combination: Elizabeth Howell

Dawn is now so close to Ceres that its pictures will soon exceed the best ones Hubble had to offer. The image above (at right) is modest compared to the space telescope, but in a planned photo session Jan. 26 Dawn will have slightly better pictures than Hubble. By Feb. 4 they will be twice as good in quality and then seven times as good Feb. 20.

The spacecraft’s images not only have science purposes, as they let investigators study the surface, but also serve as optical navigation aids. Ceres is a tiny body and hard to navigate to from far away, so as it gets closer these pictures are crucial for Dawn to figure out where to go next.

Dawn will get its close-up of Ceres in the spring when it arrives at the dwarf planet. To get the latest on the mission, check out the entire Google+ Hangout from yesterday.

December 12, 2014December 23, 2015 by Elizabeth Howell

Opportunity Mars Rover Plagued By Flash Memory Problems, But Carries On

Opportunity's robotic arm is cast in shadow as the Mars rover explores the rim of Endeavour Crater on Sol 3,854 (Nov. 26, 2014). Credit: NASA/JPL-Caltech

NASA’s aging Mars rover is still struggling with Flash memory after several months of controllers trying to work around frequent resets and amnesia events, according to a recent update.

The Opportunity rover is coming up on its 11th anniversary of landing on Mars, and is busy exploring the rim of Endeavour crater, en route to a region that could have clay minerals (showing evidence of water). But the rover has been dogged by frequent memory problems that forced a reformat in September, with only partial success.

While the updates have said the rover is still performing science, NASA says in a Dec. 4 to Dec. 9 update of the mission that the Flash memory was reformatted once again, and that controllers don’t plan to use any of it for the time being. Flash is useful because it retains data even when the rover is turned off. NASA is instead storing “data products” in RAM format.

“Longer term, the project is developing a strategy to mask off the troubled sector of Flash and resume using the remainder of the Flash file system,” NASA stated.

Highlights of the rover’s 10-year mission on Mars are in this Universe Today article, and also in the video below.

December 11, 2014December 23, 2015 by Elizabeth Howell

How To Take Photos Of Earth While Whizzing At 17,000 MPH

A timelapse photo taken by Don Pettit on the International Space Station. Credit: Don Pettit/NASA

When you’re flying above Earth in a spaceship or space station, taking a clear picture below is more than a point-and-shoot job. As NASA astronaut Don Pettit explains in this video, you need to account for the motion of your little craft to get the best pictures below. And Pettit should know, being a photographer who captured many stunning timelapses in space.

“Apart from everything else an astronaut does on orbit, photography is actually part of our job,” Pettit said in the video. “We take pictures of Earth and the surroundings of Earth, the upper atmosphere. These pictures, in themselves, represent a scientific dataset, recorded now for over 14 years.”

The video is called “From Above” and is a production of SmugMug films, who also did an interview with Pettit. As it turns out, much of the photography taken in space is not of Earth — it’s engineering photography of window smudges or electrical connections to help diagnose problems happening in space.

“These things need to be documented so the images can be downlinked for engineers on the ground to assess what’s happening to the systems on space station,” Pettit said in the interview. “We get training specifically on doing these engineering images, which, for the most part, are not really interesting to the public.”