On the first full day of the American Astronomical Society Conference in Seattle, my students and I attended a variety of plenary sessions, poster sessions, parallel sessions, and a follow up meeting of all the NITARP groups. I also had the unexpected opportunity to meet one of my personal heroes and to meet someone who was about to become somewhat famous.
After getting up and getting ready, I called my students to see if they wanted to meet for breakfast. One thing I find irritating about nice hotels is that they don’t provide free breakfasts – I guess they figure that if you can afford a room at over $150 per night, you can afford your own breakfast. This is why I usually choose to stay at places like Comfort Inn or Days Inn – they provide free hot breakfasts and their rooms and beds are almost as nice – certainly nicer than what I have at home. And they cost less. But since the NITARP program was paying my way and providing a per diem for meals, I wasn’t complaining.
Julie and Rosie met me downstairs in the lobby and we ate next door at the restaurant associated with our hotel. The breakfast was good, but overpriced and not very filling. My other students opted out of breakfast so they could sleep in a bit.
Van Allen’s Pants
The conference began officially with a plenary Kavli Foundation Lecture by Dan Baker on his work on Earth’s magnetosphere with the SAMPEX mission. It is expected that everyone attend the plenary sessions – nothing else is scheduled during these times. There was a large crowd attending and I sat toward the back. He told of how the Russians could have beat us to discovering the Van Allen Radiation Belts. There was an instrument package with Sputnik II (which contained the dog Laika). The probe reached apogee over Australia at a high enough altitude to be in the radiation belts, but the Australians refused to share the data with the Russians. So Explorer 1 with its Geiger counter onboard found out the belts were there, and Van Allen (who suggested putting the Geiger counter in the probe in the first place) made the cover of Time magazine. Van Allen was Dr. Baker’s mentor. When Van Allen was asked by a reporter what the belts were good for, he replied, “To hold up Van Allen’s pants!” Apparently, he hated the term “belts” and preferred to call them radiation “zones,” which is a more accurate description.
The SAMPEX mission had an elliptical polar orbit, and as it dipped in and out of the zones, found out some interesting things. First, there are three, not two, radiation zones or layers. The newly discovered outer ring acts as a storage area for atmospheric ions. Second, radiation from the Sun has profound affects on the zones. Over time, the zones weaken, but whenever Coronal Mass Ejections (CMEs) are blasted off the surface of the Sun, they spiral out (because the Sun rotates) and as they interact with the Van Allen zones, they cause a stripping and decoupling of the ions in the zones, weakening them rapidly. But the CMEs also provide new particles that re-energize the zones, causing a reconnection within tens of minutes to hours. During these decoupling events, Earth’s energy and communication grids are vulnerable since high-energy electrons can penetrate through. Third, there are gaps or slots between the zones with fairly sharp edges.
After his lecture, I walked to the main hall to look through the posters. I didn’t stay long – just got a quick overview and snapped a few pictures. I stopped by the SOFIA booth to talk to Coral Clark and see if we were getting together for dinner.
I attended a parallel presentation session on exoplanet atmospheres, where graduate students give five-minute presentations on their work with two minutes for Q & A. I was intrigued by the title – it seems amazing that we can tease any information about atmospheres out of the exoplanet data from Kepler, where the signals for the planets themselves are so hard to ferret out of the noise. But you would be surprised, as I was, how much can be discovered from those slight dips in the light curve of a star.
Nick Cowan spoke on his study of Hot Jupiter atmospheres and the difficulty of inferring conclusions from such uncertain data. They did manage to get some good reads on the daytime temperatures of some planets. Joel Schwartz spoke further on how these temperature readings provide some clues as to the circulation, radiation, and albedos of the exoplanets.
Bjorn Benneke studied oxygen-rich Hot Jupiters to model where the planets formed and if they migrated inwards, which is a big question concerning Hot Jupiters. Our best models of planet formation say that a Jupiter-class planet with a thick gas atmosphere must form away from the star, or the star’s stellar wind would have stripped all the gases away. So conventional wisdom says they formed further out and migrated in. His analysis shows discrete cloud layers and compositions on some planets, others with hazy atmospheres and a top cloud deck.
Soon to Be Famous
The final presentation in this session was on the Planet Hunters project, where anyone can access Kepler data to look for planets. Ran like the other Zooniverse projects, each light curve is vetted by several citizen scientists. If one of them disagrees with the others, it is looked at by a moderator who makes the final decision. The presenter said that their search also looks for RR Lyrae and other variable stars. She gave her e-mail address at the end, but I was beginning to get sleepy in the warm room and my writing trailed off. In my notebook, it reads: “Tabetha.boy…..” before trailing off completely. Yes, it was Tabetha Boyajian, a postdoctoral student at Yale University who heads the Planet Hunters program.
Little did I know (or she, for that matter) that within a year of making this presentation, she would become famous for Planet Hunters detecting the weirdest star yet spotted in the Kepler data – KIC 8462852, now called Tabby’s Star or the WTF (“Where’s the Flux?”) Star. It is a real space oddity, an F-type star in Cygnus about 1480 light years away. Instead of the regular, small dips in the light curve that indicate a nicely behaved exoplanet, this star has frequent, irregular dips of as much as 20% of the star’s light, as if it is orbited by large chunks of something much too big to be a planet. Tabetha’s analysis suggested it might be swarms of comets, as shown in the artist’s drawing. But recent further analysis shows that it would take 680,000 comets, each over 200 km across, to make that kind of dip in the star’s light. Not very plausible. There is no infrared excess, so there is no warm dust that one would expect from a collision scenario.
So what is causing it? One suggestion is that an alien civilization is building some kind of megastructure around the star, perhaps a Ringworld or Dyson Swarm. But more recent detailed analysis of historical photographic plates shows that the star has gradually dimmed 20% over the last 100 years. It’s hard to think of any civilization having the wherewithal to cover 20% of their star in that short of a time period. There is none of the waste infrared energy that one would expect of an alien structure, and SETI searches during the fall of 2015 have found no evidence of signals. It just gets weirder and weirder. Several things are certain: Tabetha Boyajian’s presentation at the 2016 AAS will be very well attended! And it proves the importance of citizen science studies – no automated system would have discovered this. Many studies are underway as I write this to observe the star and determine if the dimming is caused by cold dust (from comets or Kuiper belt collisions) or if the obscuring objects are more solid. Stay tuned!
Finding lunch was a bit problematic, but there was a small sandwich shop along the walk between the Hyatt and the Convention Center that I went to. Our NITARP group met together at some tables set up at the back of the main hall to eat lunch and plan our schedule for the next three days. Tuesday is the astronomy education day, with concurrent sessions and posters. I will have my individual poster to present all day, and we had our NITARP educational poster as well. We set up times for who would do what. The science poster would be presented on Wednesday, so we assigned groups of students to different times, with teachers to keep an eye on them.
Meeting a Personal Hero
After lunch there was a plenary session on space exploration policy featuring Dr. John Logsdon of George Washington University and the Space Policy Institute. I wanted to attend to see what the future of NASA and space exploration was likely to be (or should be). I was sitting toward the back when two of John Gibb’s students, Ashwin and Matt, walked past and saw me. They said they were going to sit on the front row and invited me to join them. Now I knew that the front row is where the Big Wigs sit – NASA directors and AAS presidents and the like. I figured that the students would be able to get away with sitting there because no one would expect them to know the etiquette of these sessions, but I also decided to join them to make sure they didn’t commit any major faux pas.
We sat down just to the side of the podium and I was crossing my fingers that no one would ask us to leave. It was several minutes before the session, and a photographer was taking photos of Dr. Logsdon at the podium in front of the big AAS sign. I was watching this when a man sat on my right, and I turned to discover it was Dr. Paul Hertz, Astrophysics Director for NASA, whom I had met at the reception at AAS in National Harbor last year. He was looking at notes, but I decided to be bold and introduce him to Matt and Ashwin. I re-introduced myself. He remembered me from last year and that I was part of NITARP and SOFIA. I introduced him to the students, and he said that this was a great opportunity for them because not many high school students ever get to come to professional astronomy meetings, let alone present. Then he said, “In fact, you really ought to meet my boss!” He tapped the shoulder of a man standing in front of us with his back turned. The man turned around, and it was John Grunsfeld, head of NASA’s Science Mission Directorate and a six-time astronaut. Three of those missions, he led the repairs/refurbishing of the Hubble Space Telescope and probably has more space walking time than anyone else on the planet.
Dr. Grunsfeld was very gracious, talking with us for several minutes. I mentioned I was here for NITARP but had also flown on SOFIA as an Airborne Astronomy Ambassador, and it was an amazing experience. He said that he and Dr. Hertz kept meaning to fly on SOFIA (since they are over it) but that getting his schedule to work out to take a trip to Palmdale, then sleep during the day, attend the briefing, and fly all night on SOFIA was hard to arrange. I encouraged them to try, and that it was worth the effort.
(Several months later, when looking through some press releases from SOFIA, I came across an article and photos showing John Grunsfeld on SOFIA, flying with Kathleen Freddette, a Cycle 0 AAA from Palmdale, in February 2015. That was only a month and a half after we had this conversation. I give myself credit for convincing him to do this!)
Drs. Grunsfeld and Hertz were pulled away by other matters as the session was about to start, so I turned to Ashwin and Matt and said, “Do you have any idea who that was? He’s the director of all science missions for NASA and a six-time astronaut!” I think they were duly impressed.
The Future of Space Policy
Dr. Logsdon asked what we should expect of a space program. We spend more on space than the rest of the world combined, and since 1971 the U.S. space program has been plagued by analysts who say we don’t have clear goals for what we want to accomplish in space. Pres. Kennedy’s challenge to go to the Moon was backed up by a 100% increase in funding for all aspects of space exploration – not just the Apollo program. It would be the equivalent of boosting NASA’s budget today to $40 billion. It’s true that much of this went to building the initial infrastructure we’re still using, but as Carl Sagan put it “A rising tide floats all boats.”
Pres. Nixon’s administration valued building capabilities over going on beyond the Moon. VP Spiro Agnew’s Blue Ribbon Panel recommended building the space shuttle to service a large space station, from which we could then go on to Mars. But Nixon saw it as too expensive and trimmed the ambitious plan. Nixon wanted space to take its place as just one of a rigorous system of national priorities.
Since the 1970s things are largely unchanged. Pres. Obama has not put the resources behind his rhetoric, and NASA’s real budget adjusted for inflation continues to slowly dwindle. Dr. Logsdon was on the Columbia accident review board in 2003 and part of their findings was that NASA was straining to do too much with too little, like trying to squeeze a 20 lb watermelon into a 2 lb bag.
But given its limited resources, NASA is doing OK. HEDS (the Human Exploration and Development of Space) gets the most public attention and faces the most uncertain budget. The President is also making direct decisions about HEDS instead of simply taking the recommendations of his scientists. Planetary Science, Robotics, and Astrophysics tend to have a more constant budget of $5-$6 billion per year without a lot of debate in Congress. The fact that they do decadal surveys and meet their goals speaks to the stability of these programs.
As for HEDS, we continue to lack a strategic focus that everyone can get behind. He predicted the most likely outcome is that we will continue to muddle along with a weakly supported program, unable to make any truly bold explorations like going on to Mars. The only way this could change is if we get a president who truly supports space exploration or if we share the expense with other countries. As for civilian space programs such as SpaceX and the X-Prize, it takes a country to truly lead the way and show vision for such an undertaking. We’re not racing anywhere anymore, so it will take a coalition of countries with a compelling goal for us to move outward again.
None of what he said was new to me, and I’ve written about it in previous posts. I simply wish we had a compelling reason to explore Mars and beyond. The China Challenge simply isn’t getting anyone excited – so what if their stated goal is to return to the Moon and go beyond? I fear that in the next 50 years, China will surpass us in space simply because we lost the motivation. There’s no reason the first flag on Mars must be American. I guess I’m glad that I speak Chinese . . . because when we stop progressing, stop innovating, stop exploring, we will cede our spot as the leading country to whoever doesn’t stop. Perhaps those with vision will need to move to China.
After the plenary session I went to a parallel session on the galactic center, the Milky Way, and streams of stars. I was astonished again by how we are now able to determine which stars belong to which populations, and that there are streams of star formation that can be traced through space and time.
Lauren Campbell spoke of hypervelocity stars in the Sloan Digital Sky Survey. They have identified 18 O and B stars and 20 G and K in a 5 kiloparsec sphere, and are now looking for F stars. They’ve found over 15, and all are metal poor. These HVSs are moving at 600-1300 km/sec and are going too fast to stay bound to the Milky Way – they’re headed out into the intergalactic void. They hope to find a population of stars already ejected from the Milky Way. Their explanation is that these stars were once part of binary systems, possibly close to the galactic center, and were ejected by gravitational interactions.
Matthew Newby spoke on the Sagittarius Dwarf Galaxy Tidal Stream. As this dwarf galaxy on the opposite side of the Milky Way from us merges with us, at least two streams of stars are being pulled out. He had to look at the CCD and CMD turn-off points to eliminate any blue stragglers, and account for the Virgo overdensity (a bright stream probably not associated with the Sgr Dwarf). Actually, what amazed me the most about this presentation is that I actually understood all of it. I know what he means by turn-off points and blue stragglers.
Branimir Sesar looked at the Ophiucus Stream, a group of 12.7 Gigayear-old metal poor stars orbiting in a looping pattern about 9 kpc from the galactic center.
Heidi Newberg spoke of rings and radial waves in the galactic disk. By subtracting the north galactic disk from the south, they should cancel out but they don’t. It produces a corrugated wave pattern. These might be ripples caused by the infall of the Sagittarius Dwarf.
After supper, we had a meeting of all the NITARP groups, present and past (and teachers for the future) at 7:00. We asked what had been effective, what needed to be improved, with anonymous comments. I commented that I wished the students had had more to do with the final writing and analysis on the poster – it felt that the teachers took over for them, even though they will be presenting it. It was a large group, and we did some small group brainstorming on different questions.
I met Tim Spuck for the first time, and he told us about his new NSF funded program to take a group of astronomy educators to Chile to see the various telescope systems there, including the ALMA array. I decided I wanted to apply for this program, even though I would have to come up with my own $1800 airfare.
We took a large group picture, and by the time I got back to my room I was exhausted and brain dead. There is so much to see and do at these conferences, and this had been a very full day.