Category Archives: astronomy

astronomy, New Horizons mission, Pluto

“It Just Gets More Exciting from Here!”

Leave a comment

Possible Pluto Features Sighted

The news from the New Horizons mission just keeps getting better. The latest images, combined into an animation, show what might be a polar cap on the dwarf planet. It’s the best picture yet of this distant, tiny world. The good news is, as the spacecraft gets closer, the images are just going to get better!

 

The 3x-magnified view of Pluto highlights the changing brightness across the disk of Pluto as it rotates. Because Pluto is tipped on its side (like Uranus), when observing Pluto from the New Horizons spacecraft, one primarily sees one pole of Pluto, which appears to be brighter than the rest of the disk in all the images. Scientists suggest this brightening in Pluto’s polar region might be caused by a “cap” of highly reflective snow on the surface. The “snow” in this case is likely to be frozen molecular nitrogen ice. New Horizons observations in July will determine definitively whether or not this hypothesis is correct. In addition to the polar cap, these images reveal changing brightness patterns from place to place as Pluto rotates, presumably caused by large-scale dark and bright patches at different longitudes on Pluto’s surface. In all of these images, a mathematical technique called “deconvolution” is used to improve the resolution of the raw LORRI images, restoring nearly the full resolution allowed by the camera’s optics and detector. Courtesy: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

You might wonder how a spacecraft traveling at 14.57 kilometers per second (relative to the Sun), now more than 31.86 astronomical units (that’s nearly 32 times the distance between Earth and the Sun), can send back increasingly better images? It starts with a camera called LORRI, which stands for Long Range Reconnaissance Imager. It’s a small, but powerful instrument, weighing less than 20 pounds and using up less than six watts of electricity. The “guts” of the instrument is a 8.2-inch telescope aperture that focuses visible light onto a CCD. Think of it as a digital camera attached to a telescope. It’s quite small, but powerful and is built to withstand the cold, radiation-filled vacuum of interplanetary space. All of its data are collected on board, and then sent back to Earth via an X-band communications system that includes several antennas.  They communicate with the Deep Space Network, which then relays the data to the waiting team members. You can actually see when New Horizons is communicating with Earth at DSN Now.

As New Horizons gets closer to Pluto, its images will improve dramatically. Already, it has shown us that Pluto is a world with surface features. Now, we just have to wait to see what those features are. Starting in mid-May, the images will start to be better than Hubble quality resolution, and that’s when things will really start to get exciting. At flyby, LORRI will be providing looks at the surface that will resolve features only 50 meters (about 150 feet) across. That means we’ll be able to see things such as craters, cliffs, chasms, whatever it is that is making Pluto’s surface look alternately bright, dark, and interesting.

I was listening to the New Horizons team talk about these latest images via telecon yesterday and could really hear the excitement in their voices. My friend Alan Stern (the PI for the mission) whom I’ve been talking with quite a bit in these last few months’ run-up to the flyby, summarized the situation for all the listeners. “After traveling more than nine years through space, it’s stunning to see Pluto, literally a dot of light as seen from Earth, becoming a real place right before our eyes,” he said Alan Stern. “These incredible images are the first in which we can begin to see detail on Pluto, and they are already showing us that Pluto has a complex surface.”

At closest approach, the spacecraft will be about 12,500 kilometers above the surface of Pluto, and that will really give LORRI and the other New Horizons instruments something to show us. So, stay tuned, as they say.

Pluto huggers everywhere: our time is coming!

 

astronomy

Science and Fandom at Denver StarFest

Leave a comment

Fans Explore Hubble, Pluto and Beyond

Groot greets a young fan at StarFest 2015. Carolyn Collins Petersen
Groot greets a young fan at StarFest 2015. Credit: Carolyn Collins Petersen

Every year I visit with the denizens of dozens of different worlds at the annual StarFest Entertainment Con in Denver (organized by Starland.com). These are the Star Trek and Star Wars citizens, along with Dr. Whovians, Middle Earthers, visitors from the many different flavors of anime and comic-dom, and others of the creatively anachronistic bent.

Giving a talk about Hubble Space Telescope at StarFest. Carolyn Collins Petersen
Giving a talk about Hubble Space Telescope at StarFest. Credit: DMGice

My job at the Con is to give science talks. It was the 13th or 14th con I’ve spoken at for the StarLand people, and I began doing them back before I started grad school. Of course, I’m a Trekkie from WAY back, so I get my geek on at the same time I’m sharing science with others.

This year I focused on exoplanets—the many worlds fans have visited in science fiction and fantasy—by way of looking at those discovered by astronomers. I also gave a talk commemorating the 25th anniversary of the launch of Hubble Space Telescope, and even before the talk started people were stopping to ask when it would be so they could get there early for a seat. The talks were standing room only, we had lots of time for Q&A, and there were many hallway conversations about astronomy and space exploration.

Each time I talk at StarFest (and even when I’m speaking to audiences in other venues) I get a LOT of questions about Pluto. You know what question people ask the most: why isn’t it a planet? This year, I decided to bring Pluto with me so folks could get first-hand information from a real-life Pluto explorer: Dr. Alan Stern. He’s an old friend from grad school, and the Principal Investigator for the New Horizons mission encounter with Pluto. I figured, if anybody could excite people even more than they already ARE about this dwarf planet, it would be Alan.

Alan Stern at StarFest, talking about Pluto.
Alan Stern at StarFest, talking about Pluto. Credit: Carolyn Collins Petersen

He took the stage on Saturday morning and from the first words, he had the audience enthralled as he talked about the mission, Pluto’s characteristics, and yes —why the IAU decision in 2006 was wrong. Simply put, planetary scientists are the best ones to make the decision about what is or isn’t a planet, and the criteria “voted on” by the remnants of the IAU meeting that year just don’t hold up in a court of planetary definitions. Particularly since we’re still figuring out what the solar system actually contains.

Right now we know of three times more dwarf planets than we do of actual “planets”. Alan explained it all very well, and the Q&A after his session went on for more than 30 minutes. It was a hit and they’d like to have him back again next year to do a follow-up.

A screen capture of my interview with journalist Presley Alexander. Courtesy: Presley Alexander.
A screen capture of my interview with journalist Presley Alexander. Courtesy: Presley Alexander.

One of the most interesting experiences I had at StarFest this year was taking part in media interviews. The ones that stand out were with DMGIce, a local video producer with a world-wide audience, and a fascinating interview with a young lady named Presley Alexander who is not only a science whiz, but has her own YouTube channel. She is interested in a great many topics and makes videos as part of her home schooling. She was interviewing as many of the guest speakers at StarFest as she could get, and both Alan and I sat down for interviews with her. She was amazing, energetic,  professional, well-prepared, and it was a pleasure to talk with her. Check out her channel when you get the chance.

A screnshot of Alan Stern with Presley Alexander. Courtesy Presley Alexander.
A screen capture of Alan Stern with Presley Alexander. Courtesy Presley Alexander.

I’ve always known that there are many science-savvy people attending these cons, even among the other guest speakers. This year we had artist Rick Sternbach (best known for his Star Trek work) and terrifically well-versed in spacecraft (since he builds models), and actor Armin Shimerman (who played Quark on Star Trek: Deep Space 9), who I had a marvelous conversation with about dark matter.

People like astronomy and space—not just at StarFest. I’ve spoken at Shore Leave and WorldCon, and found the same thing to be true there. Among all the folks dressed as Klingons, Storm Troopers, Princess Leia, Sailor Moon characters, hobbits, wizards, Spiderman, Groot, Wonder Woman, and so on, there is a deep curiosity about the universe around us. It shouldn’t be a surprise—I’ve always thought that if your mind can handle all the interesting stories told in science fiction and fantasy, comics, and movies, you should be able to handle the wonders of the cosmos. Or maybe it’s the other way around.

Either way, judging by the folks who flocked to my two talks and Alan’s presentation, I think that’s all still true. I’ve been asked to organize a more extensive science track for StarFest in the next few years, which I think is a pretty good indication that science and fandom can and do co-exist. Wish me Qa’plah!