From Today I Found Out:
The beam itself measured 2000 gray as it entered Bugorski’s skull and about 3000 gray when it exited on the other side. A “gray” is an SI unit of energy absorbed from ionizing radiation. One gray is equal to the absorption of one joule of radiation energy by one kilogram of matter. An example where this is commonly used is in X-rays. For reference, absorption of over 5 grays at any time usually leads to death within 14 days. However, no one before had ever experienced radiation in the form of a proton beam moving at about the speed of light.
I’m posting this out because it immediately made me think of the interview we did with Dr. DiRuggiero for last week’s 365 Days of Astronomy podcast:
The organism we’re working on at the moment is Halobacterium. They’re fairly resistant to radiation. We measure the resistance to radiation as the D10, which corresponds to the radiation doses for which 10% of a population survive. So the D10 of the organism, that is called the wild type. The regular organism is five kilo Gray—that’s measured radioactivity—which is pretty high. This is 5000 Gray, and humans are killed by five Gray. Those survive 5000 Gray; humans died with five Grays.
As mentioned on the email list, this year we’re attempting to do a little astrobiology public outreach and education. Our first series of efforts are interviews with faculty and researchers here at Johns Hopkins who are actively involved in astrobiology-related research. These interviews will be featured on the once-a-day podcast site, 365 Days Of Astronomy. We’ve done two interviews so far, and the first one goes live on that site tomorrow. It’s an abridged, 12-minute version of our discussion with Dr. Jocelyne DiRuggiero of the Biology department about her research with halobacterium and hyperthermophiles, extremophiles that live in high salt and high temperature regions, respectively. Below I’m attaching the full, 24-minute interview as well as the transcript.
Let us know, either through the comments section below or on the email list, if you’re interested in helping out by suggesting someone to interview, being interviewed yourself, or anything else you’re interested in trying (it’d be nice if we had a theme song….). Our next interview is with Dr. Naomi Levin of the Earth & Planetary Science department. It should be going up in the next month and will be featured on 365 Days Of Astronomy in April.
Now, on with the podcast!
Studying extremophiles on Earth to understand life in space
With the Kepler Mission’s discovery of 4 potential Earth-sized planets orbiting in their host star’s habitability zones, the main question about life is no longer “Is there life out there somewhere?” Instead we must ask, “Exactly what sort of life could exist on these strange planets?” For today’s 365 Days Of Astronomy podcast, the JHU Astrobiology Forum’s Adam Fuller begin answering this question by speaking with Dr. Jocelyne DiRuggiero, an associate research professor in the Biology department at Johns Hopkins University, about her research with microorganisms here on Earth that live in environments so hellacious, they could easily be thought to be from another world.
Continue reading Interview with Dr. Jocelyne DiRuggiero
This Friday, February 4, 2011, at 12:30pm in John Bahcall Auditorium at the STScI, Dr. Vikki Meadows from University of Washington will give the next Planets, Life, and the Universe Astrobiology Lecture. The title of her talk will be “The Virtual Planetary Laboratory: Modeling Signs of Habitability and Life on Extrasolar Planets.” Here are the details:
In the coming decades, the search for life outside our Solar System will be undertaken using astronomical observations of extrasolar terrestrial planets. To better inform our search, the NASA Astrobiology Institute’s Virtual Planetary Laboratory team uses a suite of computer models to explore the interaction between a terrestrial planet and its parent star. The resulting models allow us to simulate extrasolar terrestrial planetary environments and spectra, and to define and quantify likely signs of planetary habitability and life. This talk will discuss the VPL models and results to date, including the detectability of planetary habitability and potential signs of life from alternative biospheres.
A reminder to everyone, we have a meeting this week! It’s going to be Wednesday, February 2nd at 5pm in Mudd 23. We’ll have pizza and drinks, talk about some of the public outreach projects we’re working on this semester, and there’ll even be a few presentations. I’ll give a run down on the latest announcement from Kepler. Dan will give us a first look at the issue of prebiotic chemistry of lipids. There’s also a third talk scheduled that we’re still working to get filled. So come on out for our February meeting. As they say in the corduroy world, all whales welcome!
Post-meeting update: here are slides we used in the talks:
I’m planning an astrobiology booth for the Physics Fair at Johns Hopkins in April, so I’m exploring the outreach-and-education section of the NASA Astrobiology website to find materials. Here are some fantastic things I’ve found.
This lets you see how long ago two evolutionary lines diverged: http://www.timetree.org/
My first test was human vs. wombat (~150 million years ago): http://www.timetree.org/time_query.php?taxon_a=29139&taxon_b=9606
But also interesting is human vs. brewer’s/baker’s/biologist’s yeast (~1300 million years ago!—1.3 billion): http://www.timetree.org/time_query.php?taxon_a=4932&taxon_b=9606
This is an unbelievable historical perspective on our discovery of other planetary systems: http://planetquest.jpl.nasa.gov/timeline/timeline.html
I wish we could bring back some of these guys, like Giordano Bruno, and say “Look, you were right, we found other solar systems!” Really makes me cry. The exoplanet counter does not change from zero until 1992.
Also the Extreme Planet Makeover activity at that PlanetQuest website a good way to get a feel for how physical parameters (star type, distance from star, size of planet) change the nature of the planet (balance of solid, liquid, gas, etc.).
Adventure through a microbial community—goofy but informative: http://microbes.arc.nasa.gov/movie/large-qt.html
It’s that time again to schedule our next meeting. We’re shooting for the first week of classes. There’s a doodle poll set up, so mark your preferred day and time. We’re closing the poll on Friday, January 21st at 5pm, so mark your preferences soon.
When we have the meeting may dictate who is available to give presentations during the meeting, so right now we can’t make any promises about topics. But we will soon!
I mentioned this about a month ago to this list, so I’d like to remind everyone about a great public outreach opportunity. We’re currently signed up for several slots in the 365DaysOfAstronomy.org podcast. This is a podcast open to submission from all over the world about any topic of interest related to astronomy. As such, people from all over the world with hugely varying degrees of expertise download and listen to this podcast. This is a great opportunity to get involved in public outreach, get your name out in front of the general public, as well as an important addition to your CV or grad school application. If you’d like to know more about the site and the podcast in general, I suggest reading through their “about” page.
I started doing these as an undergrad at Columbia University. The grad students there mobilized to establish a “Columbia Mondays” recurring series during 2009. We did quite a bit of them, and you can find links to all of them from here. I was thinking we could do something similar for astrobiology at JHU. We can do podcasts on any topic you like–current events, your research, hobbies, etc–as long as you can link it back to astronomy/astrobiology in some way. I’ve done about 6 of these myself, ranging from a discussion of the Galileo probe’s discoveries at Jupiter, the science behind detecting moons around extrasolar planets, to an exploration of my interest in the history of astronomy.
Doing a podcast requires writing a transcript, recording yourself reading the transcript, and then uploading everything to the site. The writing part requires the most time and research, but if we do this as a collaborative effort (someone writes about an area of interest, the rest of us providing copy-edit and revisions) it should go quickly. Then, using David Coren’s suggestion, we can record and edit the podcast at the Digital Media Center in Mattin in just a couple of hours.
We have four dates reserved on the calendar: Feb 12, April 25, Sept 26, and Nov 28. The very first one is Darwin’s birthday. We should do something Darwinian related. Let me know if you’re interested in doing this first one. We’ve got to have it submitted February 7th.