Pluto: All Known Moons Accounted For

We Stand on the Threshold of Discovery

New Horizons spots all five of Pluto’s known moons. Courtesy New Horizons mission/NASA/ Johns Hopkins APL

Ten years ago the New Horizons spacecraft lifted off on the journey of a lifetime—aimed at Pluto and beyond. This week, less than 60 days before its closest approach to the famous dwarf planet, the spacecraft is less than an astronomical unit away from its main target. It’s running just fine, and searching for new moons and a possible ring system around Pluto. It has already spotted Nyx and Kerberos, the dimmest of Pluto’s known moons. Any moons or rings that it finds from here on out are worlds that have never before been seen.

The mission to Pluto is catching people’s hearts and minds, and not just because Pluto has been the center of discussion about its planetary status. This distant world has always been something of a goalpost in solar system studies. Until the discovery of more-distant dwarf planets in the Kuiper Belt, Pluto was considered the frontier—the last stop before the stars. In a sense, it still is. New Horizons will swing by Pluto and Charon, and possibly two other smaller worlds in a few years, but after that, the mission’s adventure lies in the stars.

New Horizons is guiding our view of a distant, cold, lonely part of the solar system. From here on out, each of its images will show us something we’ve never seen before now. Its collection of instruments will tell scientists what the conditions are like at this lonely outpost: how cold it is, what the solar heliospheric influence is in this region of the solar system, and possibly what’s hiding beneath the surfaces of Pluto and Charon. Not to mention what’s ON those surfaces. Will we see craters? Geysers? Giant canyons? Cracks?

What do we already know? Pluto’s surface itself is quite reflective, like a fresh snowfall. It also has large markings that range from bright to dark. The surface is covered with ice made up of molecular hydrogen as well as varying amounts of what are called “hydrocarbons”. These are methane and ethane, along with carbon monoxide ices. As of now, that’s about all the scientists know. But, again, in the coming weeks, the view is going to improve dramatically.

What’s happening with the atmosphere of Pluto? We know that much of the thin blanket of air around Pluto is leaving this world through a process called hydrodynamic escape. What drives that?

What’s going on beneath Pluto’s surface? And, for that matter, beneath Charon’s? New Horizons won’t be able to peek beneath the ices, but it can measure the masses of both worlds, and that will give incredible insight into what’s happening in the cores of these two worlds.

From here on out, Pluto is going to surprise us each week and I’ve been following this story and writing about the mission for many months now. If you’ve been following my Pluto and New Horizons stories on this blog, or reading my work at Space.About.com, you’ve seen how fascinating this system is. This mission has been a long time coming. The science teams are already busy with data about the Pluto system that is streaming back to Earth each day. I’m ready to learn more, and I hope you are, too. Stay tuned!

 

Griffith Observatory Turns 80

Celebrating 8 Decades of Astronomy Outreach!

Griffith Observatory in Los Angeles. Photo by Carolyn Collins Petersen.

We went to Los Angeles last weekend to celebrate the 80th birthday of the venerable Griffith Observatory. It was 80 years ago today (May 14th), that the observatory opened its doors, and over the years it has served millions of people wonderful views of the sky from its telescope and under its planetarium dome.

Griffith has a very special meaning for me. It’s one of my favorite astronomy places in the world, and I had the good fortune to work as the senior writer for the Griffith exhibits in 2005-2006. It was a very seminal period for me, and very productive. For a science writer, such a project is a rare opportunity to share astronomy with a wide and constantly changing audience.

I was told while I was at Griffith last weekend that I ended up writing 25,000 words—essentially an astronomy book—spread across some 170 panels in the facility. I love those exhibits and if you get a chance to see them, I hope you do, too. (You can get a sneak preview of them here.)  One very cool outcome of that project was that I was subsequently asked to write exhibits for NASA Jet Propulsion Laboratory as well as the California Academy of Sciences in the years following the Griffith project. So, it’s doubly special.

Panelists at Griffith's Celebration of a Lifetime party, Monday, May 11th, 2015. From left to right: Dr. Laura Danly, Dr. John Grunsfeld, Dr. Charles Elachi, Dr. E.C. Krupp. Courtesy Griffith Observatory.
Panelists at Griffith’s Celebration of a Lifetime party, Monday, May 11th, 2015. From left to right: Dr. Laura Danly, Dr. John Grunsfeld, Dr. Charles Elachi, Dr. E.C. Krupp. Courtesy Griffith Observatory.

The Monday night party was staged by the Friends of the Observatory (Mark and I are proud members of FOTO), and featured a wonderful discussion about astronomy through the years led by Dr. Laura Danly (Griffith Observatory Curator), featuring Dr. E.C. Krupp (director of Griffith Observatory), Dr. Charles Elachi (director of NASA Jet Propulsion Laboratory), and Dr. John Grunsfeld, Associate Administrator for the Science Mission Directorate at NASA (and one of the astronauts who flew into space to service the Hubble Space Telescope). It was an enjoyable evening and discussion, and you could just feel the amazing love and appreciation of astronomy that the panelists and attendees had; as well as the role that Griffith has played in bringing astronomy to anyone interested in it. You can watch the video at Griffith’s Celebration of a Lifetime Web page. It’s well worth your time.

Happy Birthday Griffith Observatory! May you have many, many more happy years of astronomy outreach through your exhibits, the Samuel Oschin Planetarium, and the telescopes.

If you live in LA, or you’re going there sometime, make Griffith one of your “must-see” stops. It’s worth at least a half a day’s visit, just to see their wonderful planetarium shows, and browse the exhibits. If you can stay into the evenings, you can often get a view through their telescope, too.  It’s a beautiful building, created to turn visitors into observers.