New Amazing Mars Flyover Videos


Doug Ellison from UnmannedSpaceflight.com has done it again… and again… and again. Here are new Mars flyover videos Doug has created from data from the HiRISE camera on the Mars Reconnaissance Orbiter. Using DEM (Digital Elevation Model)– (also known as DTM Digital Terrain Model) files provided by the HiRISE team, Doug is able to render 3-D movies of a specific location on Mars. Since he is using actual high-resolution data from HiRISE, Doug says the terrain seen in the movies has accurate vertical scaling and is not exaggerated. These new views of the Red Planet are also stunningly beautiful! The video above is of the Mojave Crater wall on Mars, and below is Athabasca Valles. And Doug says more are on the way! If you recall, Doug created the flyover video of the Spirit rover’s location that was on Astronomy Picture of the Day.
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HiRISE Makes Your Wishes Comes True

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The HiRISE science team is now taking requests! A new web tool called HiWish is now available for the high-resolution camera on the Mars Reconnaissance Orbiter which allows the public to suggest a location on Mars where the HiRISE instrument should take an image. If you don’t have a particular location, you can use the HiWish site to browse around the planet, examine the locations of other data sets, and find a place that should be imaged. The team will then put into their targeting database, and your suggestion may get selected as an upcoming observation. Furthermore, the HiWish site allows you to track your suggestions and be notified when one of your suggestions gets taken.

Maybe you could even find a really unusual feature on Mars, such as this race-track-like feature that may one day be a landing site for a future mission to the Red Planet. HiRISE images will help determine if this spot is sufficiently safe for landing, such as not too many boulders, steep slopes, or too many high speed MASCAR races — (that’s the Mars Association for Super Cool Aerodynamical Racing). If it is safe, it may be considered for the 2011 Mars Science Laboratory or the 2018 rovers that ESA and NASA are working on for a join mission.

The above image is actually a huge shield volcano in the northeast part of Syrtis Major, and near the Northwest rim of Isidis Planitia, a giant impact basin.

So, go create an account at HiWish and get wishing!

Measuring the Moon’s Eccentricity at Home

View of the moon at perigee and apogee

Caption: View of the moon at perigee and apogee

As a teacher, I’m always on the lookout for labs with simple setups appropriate for students. My current favorite is finding the speed of light with chocolate.

In a new paper recently uploaded to arXiv, Kevin Krisciunas from Texas A&M describes a method for determining the orbital eccentricity of the moon with a surprisingly low error using nothing more than a meter stick, a piece of cardboard and a program meant for fitting curves to variable stars.

This method makes use of the fact that the eccentricity can be determined from the ratio of the mean angular size of an object and one half of its amplitude. Thus, the main objective is to measure these two quantities.

Kevin’s strategy for doing this is to make use of a cardboard sighting hole which can slide along a meter stick. By peering through the hole at the moon, and sliding the card back and forth until the angular size of the hole just overlaps the moon. From there, the diameter of the hole divided by the distance down the meter stick gives the angular size thanks to the small angle formula (? = d/D in radians if D >> d).

To prevent systematic errors in misjudging as the card is slid forward until the size of the hole matches the moon, it is best to also approach it from the other direction; Coming from in from the far end of the meter stick. This should help reduce errors and in Kevin’s attempt, he found that he had a typical spread of ± 4 mm when doing so.

At this point, there is still another systematic error that must be taken into account: The pupil has a finite size comparable to the sighting hole. This will cause the actual angular size to be underestimated. As such, a correction factor is necessary.

To derive this correction factor, Kevin placed a 91 mm disk at a distance of 10 meters (this should produce a disk with the same angular size as the moon when viewed from that distance). To produce the best match, the slip of cardboard with the sighting hole should need to be placed at 681.3 mm on the meter stick, but due to the systematic error of the pupil, Kevin found it needed to be placed at 821 mm. The ratio of the observed placement to the proper placement provided the correction factor Kevin used (1.205). This would need to be calibrated for each individual person and would also depend on the amount of light during the time of observation since this also affects the diameter of the pupil. However, adopting a single correction factor produces satisfactory results.

This allows for properly taken data which can then be used to determine the necessary quantities (the mean angular size and 1/2 the amplitude). To determine these, Kevin used a program known as PERDET which is designed for fitting sinusoid curves to oscillations in variable stars. Any program that could fit such curves to data points using a ?2 fit or a Fourier analysis would be suitable to this end.

From such programs once the mean angular size and half amplitude are determined, their ratio provides the eccentricity. For Kevin’s experiment, he found a value of 0.039 ± 0.006. Additionally, the period he determined from perigee to perigee was 27.24 ± 0.29 days which is in excellent agreement with the accepted value of 27.55 days.

Galaxy Zoo is Expanding to Include a Whole New “Zooniverse”

Galaxy Zoo has been an enormously successful citizen science project; so much so, that other astronomers, as well as scientists from other disciplines, have taken notice and now they want to get in on the act of having the public help make discoveries about our world and Universe. Today, the Galaxy Zoo team has launched Zooniverse. This new website will be a platform, or “home” to a plethora of new science projects where the public can take their pick of where and how they can make meaningful contributions and discoveries.

Zooniverse became inevitable around the time that Galaxy Zoo launched in 2007,” said Chris Lintott, one of the founders of the original Galaxy Zoo, and now Zooniverse, “because it was obvious a few hours into the first day that we had hit on a way of doing science that was really powerful. And it was clear that this was not only going to work with for galaxies, but for other science as well. Soon we’ll we have solar investigations, climate science, and a lot of other citizen science projects coming online.”

For those “Zooites” who love Galaxy Zoo – don’t worry, that project isn’t going anywhere.

“Galaxy Zoo itself will remain the sort of comfortable old sofa in the corner,” Lintott told Universe Today, “so anyone who is comfortable with that can remain sitting there, classifying galaxies and discovering things. But for people who want to explore a bit further and find new and exciting places to be, we’re going to expand the Zooniverse by pointing some new data to the sofa.”

On Dec. 16 an astrophysics project will be introduced in Beta to people already involved in Galaxy Zoo and the offshoot projects: Galaxy Zoo 2, Supernova Hunt, and Galaxy Mergers. If all goes well, it will be launched “live” to the public early 2010.

With new advanced instruments and ways of gathering data, scientists in almost all disciplines are inundated with data but don’t have an efficient way to sort through, organize and classify the information. Galaxy Zoo’s success (over 51 million classifications by over 250,000 people, as well as new discoveries and several science papers published) has attracted the attention of other scientists, many who have contacted Lintott and his team, wondering if there was any way they could use that same model to have the public help with other unique science tasks.

Lintott said they have a long list of additional projects that are already under development. “In a couple of years’ time we should have some wonderful projects come online, such as studying ancient artifacts, oceanography projects, looking at Earth from space, animal behavior projects, and more. We keep getting new really great projects contacting us all the time.”

“We’ve known this has been coming for years, but we didn’t really know how to do it,” said Arfon Smith from Oxford University, one of the developers of the Zooniverse site, who has been working on how to integrate other science projects into the Galaxy Zoo model. “We needed a big project to come along that wasn’t dealing with galaxies to actually get us pointed in the right direction. The technical challenge was to make the Zooniverse a nice place to be, and to make it easy for users to move between the different ‘Zoos.'”

If you are registered on Galaxy Zoo, you’ll notice you can now access and seamlessly move between Galaxy Zoo, the Mergers and Supernova Hunt sites without re-logging in. The same will hold true for the new science projects that will be coming online on the Zooniverse in the coming months and years.

“There’s an opportunity here for people to explore a range of citizen science projects,” said Smith. “Zooniverse will be a place where people can check to see what projects they might want to work on.”

“The common thread is that each project needs the public’s help to increase our understanding of the Universe, and each will produce results that could not happen without the public,” said Lintott. “Soon, there should be a science project for everyone’s interests.”

Lintott said Universe Today readers will have to wait a little while to see what they actually are, but we will definitely keep everyone updated on the new citizen science projects as they become available.

Alongside the Zooniverse, another new website, Citizen Science Alliance, has been launched for the organizations who will be coming to the Zooniverse. “The Citizen Science Alliance involves our partners,” said Lintott, “and all of us believe that making use the public’s skills, talents and energy is not only helpful in dealing with the flood of data confronting us, but it is necessary.”

Source: interview with Chris Lintott and Arfon Smith