Astronomy.com blog : Daniel Pendick, NASA

August 2009 web extras for magazine subscribers

Karri Ferron — Tue, 23 Jun 2009 21:30:00 GMT

Now that the August 2009 issue of Astronomy is in the mail or already in hand, we’ve updated Astronomy.com with our newest web extras to give subscribers exclusive complementary information to this special issue about our return to the Moon.

Take a sneak peek inside the August 2009 Astronomy magazine.

If you subscribe to Astronomy, make sure you’re registered with Astronomy.com so you can access these great extras.

Here are this issue's highlights:

Senior Editor Richard Talcott shares a NASA video animation preview of the Constellation program that will put humans back on lunar soil in “Return to the Moon.”

Associate Editor Daniel Pendick explores the opinions on NASA’s concept of “Moon first, then Mars” in “Should we go to the Moon first?”

Pendick also explains the uncertain effects of long-term exposure to space radiation and low gravity in “What are the health risks of a Mars mission?”

Senior Editor Michael E. Bakich offers an in-depth preview of the LRO and LCROSS missions that jointly launched June 18 in “NASA's next Moon mission.”

Pendick answers the “Ask Astro” question: “How warm does it get on Mars?”

And I’ve included a few more Q&As with Frank Shu and Joan Najita in “Astro Confidential: Extending the conversations.”

Of course, we’ve also posted “Bob Berman’s Strange Universe,” “Glenn Chaple’s Observing Basics,” “Stephen James O’Meara’s Secret Sky,” and “David Levy’s Evening Stars.” There are also August’s “The Sky this Month” and five “Ask Astro” questions.

Related:

Astronomy.com's Lunar Reconnaissance Orbiter mission page

LRO scientist Michael Wyatt blogs for Astronomy

Daniel Pendick — Tue, 16 Jun 2009 19:39:00 GMT

If all goes as planned, the Lunar Reconnaissance Orbiter (LRO) will launch from Cape Canaveral either Thursday or Friday, depending on the launch of space shuttle Endeavour. Brown University professor and LRO researcher Michael Wyatt is at the launch site, and starting today, Wyatt will share his impressions of this historic mission — the opening maneuver in the United States return to the Moon — with all of you. Thanks, Michael!

We'll post Michael's updates to this article in our news section, "Exclusive: Lunar Reconnaissance Orbiter updates from mission scientist."

Your Mars questions, Dr. C answers

Daniel Pendick — Fri, 05 Jun 2009 15:33:00 GMT

The Jet Propulsion Laboratory’s Mars Exploration Program web site has a fun new feature — Ask Dr. C, “your personal Mars expert.” You can type in a simple question — the simpler, the better — and get a pretty good answer. A computer program tries to match your question with an extensive database of responses.

The real Dr. C is Phil Christensen, a planetary scientist at Arizona State University. Christensen is the Principal Investigator for the 2001 Mars Odyssey Thermal Emission Imaging System (THEMIS) instrument, and the Thermal Emission System instrument on Mars Global Surveyor.

I decided to put the virtual Dr. C through a few paces. Here’s the result.

Dr. C: Hello ... it is a great day to learn about Mars! Please feel free to ask me any questions you would like about Mars ... or even about myself.

Pendick: Does NASA really have enough money to replace the shuttle by 2014, or should we just rename the Russian space program "NASA Moscow"?

Dr. C: I am sorry, I am not sure what you are asking. You might want to try rephrasing your question, searching for it on the Internet, or visiting http://mars.jpl.nasa.gov.

Pendick: OK, fine. I’ll stick to Mars questions then. Anti-global-warming bloggers say that because the martian south pole is currently in a warming trend, this means rising global temperatures on Earth are also "natural" and not manmade. Is it just me, Dr. C, or is that the stupidest thing you ever heard?

Dr. C: I am sorry, I am not sure what you are asking. You might want to try rephrasing your question, searching for it on the Internet, or visiting http://mars.jpl.nasa.gov.

Pendick: OK! OK! I’ll throw you a bone. Here’s an easy one. Why is Mars red?

Dr. C: Mars looks red due to a combination of the fact that its surface is comprised of iron-rich minerals that essentially rust (or oxidize) and that the dust made of these minerals is kicked up into the atmosphere, giving the atmosphere a reddish hue. The Martian surface is not all rust-colored, however, because depending on the oxidation process, the minerals can be a range of colors from butterscotch to rust.

Pendick: Nice answer! So, what is the warmest it ever gets on Mars?

Dr. C: Did you mean to ask "What is it like on Mars?" or "What is Mars?"?

Pendick: No, I am asking you how warm it gets on Mars.

Dr. C: If you were asking: How warm is Mars?, the answer is: Sometimes people think Mars is hot because it is red but, due to its distance from the sun, Mars is actually very cold (its average temperature is minus 81 degrees Fahrenheit!). However, the temperature on Mars may reach a high of about 70 degrees Fahrenheit (20 degrees Celsius) at noon, at the equator in the summer.

Pendick: Just one more question for now. Do you know of an aerospace stock that will rise, say, 40 percent over the next 6 months? I need to buy a new telescope.

Dr. C: I am sorry, I am not sure what you are asking. You might want to try rephrasing your question, searching for it on the Internet, or visiting http://mars.jpl.nasa.gov.

AT LAST! The next-next big thing in space telescopes?

Daniel Pendick — Thu, 16 Apr 2009 16:39:00 GMT

Astronomers eagerly anticipate the final Hubble Space Telescope (HST) servicing mission, set to blast off May 12 from NASA's Kennedy Space Center in Florida. And they are already hard at work designing the observatory that will take over after Hubble sees its final light.

Hubble is, in the lingo of telescope engineering, a UVOIR instrument: Its 2.4-meter light-collecting mirror samples wavelengths of light in the ultraviolet (UV), optical (O), and near-infrared (IR).

The James Webb Space Telescope, slated for launch in 2013, will have a much larger light-collecting mirror — 6.5 meters — than Hubble. But it will operate in the infrared.

No one knows how long HST will continue to function after the final servicing mission. It’s been in space since 1990 — 19 years and counting.

HST’s presumptive successor is ATLAST: the Advanced Technology Large-Aperture Space Telescope. I came across a detailed report on the telescope, authored by a large group of scientists and engineers from companies and scientific institutions — including Marc Postman of the Space Telescope Science Institute.

The Postman report is part of Astro2010, the ongoing “decadal survey” in astronomy and astrophysics. Every 10 years, the National Research Council of The National Academy of Sciences undertakes the surveys to recommend scientific priorities for the coming decade. ATLAST is just one idea vying for support.

ATLAST’s primary mirror would be 8 to 16 meters wide. The 8-meter concept (pictured above) assumes a solid mirror, like that of HST. The 16-meter version would have to be an unfolding assembly of segmented mirrors, like the one on the James Webb Space Telescope. Postman’s group projects the telescope could be ready for launch by 2025. Technology development, design, and planning would cost hundreds of millions of dollars.

For one thing, ATLAST would have the ability to actually detect oxygen, ozone, water, and other possible life signs (“biosignatures”) in the atmospheres of extrasolar planets. It could probe deeper than ever into the processes that create stars. And, we can assume, it will send home spectacular images of the cosmos in even greater detail than HST has captured.

Image credit: Frassanito & Associates, Inc. and the Future In-Space Operations Working Group

The quiet Sun

Daniel Pendick — Fri, 03 Apr 2009 19:23:00 GMT

Last summer, my colleague Michael Bakich, a senior editor at Astronomy, kindly gave me a special filter that fits on the front of my 4-inch Celestron NexStar, thus allowing me to observe the Sun without turning my eyeball into a poached egg.

I looked at the Sun with the new setup. Nada. Nothing!

Thanks to this cool graphic just released by NASA, it’s clear why the Sun is so, well, boring to look at lately. We are in a deep “solar minimum,” a period in the 11 (or so) year sunspot cycle where things are as quiet as an umbrella shop on a sunny day.

Dramatic statistic time: As of March 31, there were no sunspots on 78 of the year's 90 days (87 percent). For more details, check out this well-done little report from Science@NASA.

Image credit: NASA/MSFC/Hathaway

Naked-eye supernova in Sagittarius! Duck!

Daniel Pendick — Thu, 02 Apr 2009 20:13:00 GMT

OK, April Fool’s Day is over. Some pretty clever pranks bounced around the Net yesterday, including a rumor that Admiral Adama of Battlestar Galactica fame is being considered for the post of NASA administrator.

And then there was the one about the International Astronomical Union (IAU) and Pluto. This tidbit apparently originated on the internal computer system of NASA’s Jet Propulsion Laboratory:

"Based on new observational evidence of more objects of significant size in the outer solar system, Pluto will no longer be described as a dwarf planet," said David Perel, chair of the IAU's Committee on Designations. "We will be meeting to consider a permanent name for the category of objects that Pluto falls under. In the meantime, we are describing it with the working label of 'FLR' (Fairly Large Rock)."

But my personal favorite prank appeared late in the day on the irreverent and occasionally foul-mouthed “Dynamics of Cats” blog by astrophysicist Steinn Sigurðsson. Check out Sigurðsson’s blog on the naked-eye supernova spotted in Sagittarius and the impending apocalypse.

WorldWide Telescope adds Mars Reconnaissance Orbiter images

Daniel Pendick — Wed, 25 Mar 2009 21:41:00 GMT

Megacorps are practically lining up for the privilege of disseminating fantastic volumes of astronomical images to you, John and Jane Q. Public.

Recently Google added a “Live from Mars” function to its 3-D visualization of Mars within Google Earth. The feature allows you to see images from the Mars Odyssey spacecraft.

Now Microsoft says it will let you explore images from the Mars Reconnaissance Orbiter (MRO, pictured at right) within its web-based astronomy application, WorldWide Telescope (WWT).

More than 100 terabytes (1 terabyte equals 1 trillion bytes) of NASA data, including images from MRO that has been studying the planet since 2006, will be incorporated into WWT later this year, according to Microsoft. Images from a camera aboard NASA’s Lunar Reconnaissance Orbiter set to launch in May will also be made available.

The inherent coolness of “Live from Mars” is that you can see new images from Odyssey’s THEMIS camera nearly as soon as scientists themselves — within a day or so, usually.

The unprocessed THEMIS images themselves are not exactly works of art. They are detailed, but in grayscale. The instrument that takes them works in infrared.

I am not aware of any plan to post MRO images “live” on WWT. But it would indeed be very cool if they did. MRO’s HiRISE camera takes stunning images.

It would be a win for us astro fans if a little healthy rivalry between Google and Microsoft spurred them to make even more NASA data available for us to explore in a user-friendly way, either in Google Earth or WWT.

Mars in Google Earth works in Windows, Macintosh, and Linux operating systems. The full-feature downloaded version of WWT works only on Windows machines right now. But WWT has recently made available a web-based version with all the major functions, and it runs beautifully on a Mac. No matter what operating system you run, you will be able to use the web version of WWT to look at the new MRO images, once they are available. (Note: To use the web-based WWT, you have to install a small plug-in called Microsoft Silverlight.)

If you are a true Marsaholic like me, you may also appreciate the Mars Express “web cam” that shows images of the Red Planet. It recently came back online after the craft emerged from behind the Sun. Check out the Mars Express Visual Monitoring Camera blog.

Exclusive: Q&A with Europa expert Richard Greenberg

Daniel Pendick — Thu, 19 Feb 2009 21:57:00 GMT

Richard Greenberg, a professor of planetary sciences at the University of Arizona's Lunar and Planetary Laboratory, is an expert in celestial mechanics and carries out NASA-sponsored investigations of solar system evolution and planet formation. He is also author of the current book Unmasking Europa.

After NASA and the European Space Agency chose Jupiter’s moons — including Europa — as the next destination for a major planetary exploration mission, Greenberg answered a few questions about the upcoming missions and his book about Europa, “an active oceanic world that just might be the most likely site for our first encounter with extraterrestrial life.”

Pendick: Are you surprised at all by NASA and ESA’s decision to go to Jupiter’s moons before going to Saturn’s moon Titan?

Greenberg: I think both proposed missions are exciting and both Europa and Titan are fantastic satellites to explore. As far as the competition for the next flagship in line, it is not a surprise that Europa was selected. It has been a top priority since the Galileo mission provided evidence for the global ocean. And the prospect for it being the place where we will most likely first find extraterrestrial life makes it an objective of almost existential significance!

That said, the discoveries about the Saturn system from the Cassini mission have shown us what active and exciting places Enceladus and Titan are. And the Titan Science Definition Team did a great job of developing a model mission that is really imaginative and spectacular.

In many ways the Titan mission is at least as appealing as the Europa one. So it is interesting that NASA did not simply make an either/or decision between the two missions — as was originally expected — but instead they made the announcement a prioritization, which leaves the door open to including the Titan mission as future budgetary and policy issues are addressed.

While I personally love Europa, for all the reasons I describe in my book Unmasking Europa, I am a big fan of the Titan mission as well.

Pendick: If you had to choose a few major points, what would you say the Europa orbiter will most likely tell us — and not tell us? For example, will the mission confirm the existence of Europa’s global ocean and perhaps how deep it is, but NOT tell us whether anything lives in it?

Greenberg: I personally believe that we already confirmed the existence of the ocean with our work on explaining the cycloidal crack patterns in terms of tidal stress and also with the Galileo magnetometer evidence. The new mission will have a laser altimeter to measure the height of Europa’s tides, and the radio tracking will also measure the gravitational effect of the tides. That information about the tides will further confirm the existence of the ocean. Contrary to some reports I have read, though, I do not believe the radio and altimeter information about the tides will tell us how thick the ice is.

There will also be an ice-penetrating radar that will tell us a lot — I hope — about the structure within the icy crust, which will help us understand the dynamics of the crust and the transport of materials between the ocean and the surface, which is critical for life, as I emphasize in my book.

The spacecraft will have a narrow-angle camera for super high-resolution imaging of Europa’s surface, in addition to wider-angle cameras. I hope the folks who plan the imaging will favor the narrow-angle camera, so we can really get a handle on the active processes that must be continually resurfacing Europa.

Other remote sensing will include an infrared spectrometer to identify the critical substances mixed in with the ice and a thermal instrument to map the heat distribution.

Naturally, if I were the king of NASA, I would order a lander to plop down selectively on a site where ocean material has recently been exposed. I could imagine finding marine organisms without needing to drill down very deep. But that is evidently something saved for a distant future mission.

Pendick: Too bad we all have to wait until 2026 to find out if you are right about Europa! But that leaves 17 years for us to read all about it in your book, Unmasking Europa. Tell us why you wrote the book and what we can learn about Europa by reading it.

Greenberg: I wanted to write this book because I knew several great parallel stories that would be fun to tell. The first was a fantastic science story about a satellite with an ocean containing twice the liquid water of all Earth’s oceans and an icy crust that is continually renewed by tectonic and thermal processing that links the ocean to the surface. Most of this information was in fragmentary form in the scientific literature, so I wanted to integrate it and make it accessible to any thoughtful reader.

Also, there had been a great deal of speculation about life perhaps being possible at imaginary volcanic vents on the ocean’s floor, but no one else was talking or writing about how the openings through the ice could really enhance the prospects for life in the ocean and that the biosphere of Europa, if any, would well extend right up to the surface.

There are also policy implications that had been under-appreciated. We may not need to drill down through the ice to reach life. It could lie very near the surface. That is the good news for exploration. The bad news, of course, is that we need to be very careful to avoid contaminating such a vulnerable place.

I also wanted to tell the story of how my own interdisciplinary research group had come to assemble this picture of a permeable ice layer by interpreting images of the surface in terms of our understanding of tides, and in the context of the wonderful scientific contributions of many other colleagues from other places.

And finally I wanted to tell the story of what I learned about the place of science in the framework of a large space mission. I wanted people to get an idea of how science really works. Like any creative human endeavor, it has its glorious aspects and its ugly ones. But it was always interesting and often hilarious. I just had to tell about it. These several story lines were interwoven and seemed to me inseparable, so that is how I wrote the book.

Europa vs. Titan: Which will NASA explore in its next flagship mission?

Daniel Pendick — Wed, 11 Feb 2009 18:11:00 GMT

“There is an ocean beneath the icy crust of Jupiter’s moon Europa [pictured at right]. Strange creatures could be swimming in these alien waters, but so far no missions have been sent there to investigate this possibility.”

So begins, "Hoping for Europa," an article by Astrobiology magazine Editor Leslie Mullen. Squids from outer space — who could resist?

Or will it be a balloon ride over the windblown surface of a hydrocarbon lake on Titan [pictured at lower left]?

“A hot air balloon drifts gently in the breeze, gliding over mountain ranges and vast lakes,” Mullen writes in another article, "Titan Triple Threat."

“Thick clouds extend over the entire horizon, threatening rain. The meager light that filters through illuminates one side of the balloon, making it look like a giant question mark in the sky.”

Later this week, NASA is expected to announce which moon of the outer solar system will be the target of a future $2 billion-plus “flagship mission.” It would likely be carried out as a partnership with the European Space Agency, along the lines of the Cassini-Huygens mission to Saturn.

The prospect of studying an alien ocean beckons. So does getting a closer look at Titan’s geologically active surface. The consensus seems to be that we are much more likely to find alien life on Europa than in the methane/ethane lakes of Titan. But who knows?

Either way, be patient. These missions would not launch before 2020 or so. If Titan gets the nod, expect a travel time of 9 years.

As soon as NASA decides, we’ll get back to you with some expert commentary.

The latest Wow from Google: Mars in 3D

Daniel Pendick — Mon, 09 Feb 2009 15:32:00 GMT

You have probably heard that Google and NASA have finally released the Google Mars update for Google Earth. I finally got the time to install Google Earth 5.0 and play on the surface of Mars for a bit this morning. It’s amazing.

I first heard about this project a couple of years ago after stumbling across a subculture of Google Earth devotees who were overlaying pieces of Mars on Google Earth to create simulated 3D views. It was, as they say, a “hack.” The 3D model of Earth isn’t exactly Mars, but it was possible to drape Mars surface data over it and create a reasonable cheat version of the planet. I joined their online forum and learned a lot about what they were doing.

I planned to write about it, but never found the time. The Google Mars project was apparently underway already. Now the circle is complete. Google Mars is no hack — it’s a fully realized simulated planet on your desktop.

Since joining Astronomy a couple of years ago, I’ve written a bunch of news and feature pieces about Mars. Usually they include the stunning surface images from Mars Reconnaissance Orbiter and other NASA sources. Today I finally had my first “Oh THAT’S where that is!” experience. I feel like the guy who’s been studying the elephant’s tail in such detail he missed the big wrinkly animal connected to it.

Browsing across Google Mars will catch you up on much of what we’ve seen on Mars to date. It puts it in a planetary context. You’ll never see the Red Planet the same way.

While you’re at it, don’t miss Google’s ocean update. Apparently the famed oceanographer Sylvia Earle quipped a few years ago that Google Earth should be called “Google Dirt,” because it was missing a rich, interactive data layer representing the ocean floor. Google took the bait, and with help from Earle and many other scientists have vastly enriched the information mapped to the ocean in Google Earth. Give it a whirl.

To view Google Earth's Mars mode
-Install Google Earth 5.0
-After installation, open Google Earth 5.0
-Look for the ringed planet icon in the horizontal menu bar that runs across the top of the display window
-Click the ringed planet icon, and a dropdown menu appears: "Earth, Sky, Mars"
-Click "Mars"
-Enjoy!