NASA to Propose Flagship Astronomy Mission in 2015
NASA plans to wait until 2015 to lay out a proposal for its next big astrophysics mission, a senior agency official said July 30.
(An engineer inspects the JWST’s primary mirror segments at NASA’s Marshall Space Flight Center in Huntsville, Ala. Credit: Chris Gunn/NASA)
“A new flagship mission stands almost no chance of being funded until after work is finished on the budget-busting James Webb Space Telescope, which is scheduled to launch in 2018, said Paul Hertz, director of NASA’s Astrophysics Division. But the planning can begin before JWST begins its five-year mission to study the origins of the universe.”
”’Unless a miracle occurs, our next opportunity to start a new strategic mission will be after [JWST] launches,’ Hertz told members of the NASA Advisory Committee’s astrophysics subcommittee. ‘In 2017 we hope to start [work on] a new mission. We will put that plan in front of the community [in 2015] through the mid-decade review to find out whether they think we did a good job in following the decadal survey.’”
“Hertz said he will share more details about the options being considered for the 2015 mission proposal in a draft white paper to be released to the astrophysics community ahead of the American Astronomical Society’s Jan. 6, 2013, winter meeting in Long Beach, Calif.”
“Decadal Survey” is something one hears often in the circles of professional astronomy. It’s essentially a road map of science goals and spending priorities the astronomy community draws up every ten years by some complicated process of ‘consensus’, intended to tell the U.S. federal government what it wants and how much it will cost. It’s sort of a recognition that we can’t have everything we want all of the time —obviously — so here’s the science we think is most important and how much it will cost. The survey process solicits inputs from astronomers across all branches of the field and through some bureaucratic black magic is distilled down into a thorough (but concise) report to the feds that helps guide policy decisions until the next survey a decade hence.
So, what might this major, new “flagship astronomy mission” consist of? The suggestions from the survey are (courtesy of the Wikipedia):
- Wide-Field Infrared Survey Telescope (WFIRST), a proposed space-based telescope to be located at Lagrangian point L2 that will survey and catalogue exoplanets and may help settle questions of the nature of dark energy.
- New Worlds Technology Development Program to plan and lay the groundwork for future missions to study nearby Earth-like exoplanets
These are the two leading, recommended space missions contending for the post-JWST era… at least as of 2010, when the last Decadal Survey was released. The smart money is on exoplanets these days, after other proposed missions like Terrestrial Planet Finder (TPF) and Space Interferometry Mission (SIM) were canceled in the 2000’s. The resounding success of the Kepler mission in discovering new exoplanets has really raised the profile of these alien worlds in the scientific community, and the likelihood of finding an Earthlike, “holy grail” planet has significantly increased.
JWST, a large, infrared-optimized, space-based telescope will contribute to exoplanet studies, but it’s a general-purpose facility. And its mission could last 20+ years, like Hubble. Will the new “flagship” mission be a resurrected TPF/SIM, will it be WFIRST, or something we don’t even know about yet? We’ll find out soon, at the next winter meeting of the American Astronomical Society. -JCB
Hubble Captures Time-Lapse Videos Of Stars Being Born
NPR: (Movies of jets from young stars at HubbleSite: here)
If you’re like me and maybe a little confused as to what you’re looking at, here’s some more detail (Yes, even Joe has to look stuff up sometimes):
As a star is formed from collapsing dust, ever increasing its density and energy, it begins to form a disk of dust and gas pulled in and rotated by its growing gravity. Perpendicular to this disk, like the tip of a spinning top, some gas is ejected away from the growing star in a high-energy jet. As this collides with interstellar gas, it gives off radiation, which we can observe with telescopes like Hubble.
To see the jets, we have to shift into the infrared and other spectra, as the radiation is outside normal human vision. These movies represent the first time we’ve seen the dynamics of the jets as opposed to still images. More info on protostellar jets here, you star-freaks.
In addition to being big red flags announcing the presence of young stellar objects, or YSO’s, outflows from these so-called ‘Herbig-Haro objects’ inject a considerable amount of mechanical energy into their environments. This is particularly important because stars don’t typically form alone, but rather in clusters of dozens to thousands of stars. Since stars begin as overdensities in cold molecular clouds that are unstable to collapse, even being “kicked” a little by the outflow of a neighboring YSO is enough to push these “cores” over a density threshold, causing the star formation process to formally begin. In this manner, once star formation gets started in a cloud, it can proceed in a snowball fashion as a few new stars kick off the formation of many others. -JCB
(via n-a-s-a)
Source: hubblesite.org
'First And Best': James Webb telescope's Miri instrument flies out to US
Europe shipped one of its big contributions to the James Webb Space Telescope (JWST) on Tuesday.
(Checked baggage: Miri went out on a standard passenger flight. Credit: BBC/Nick Morrish/British Airways)
“The Mid Infra-Red Instrument (Miri) was flown out of London Heathrow on a British Airways jet, bound for Nasa’s Goddard Space Flight Center. JWST will be the successor to Hubble, and aims to track down the very first stars to shine in the Universe. Miri has been built by a pan-European consortium led from the UK and Nasa’s Jet Propulsion Laboratory (JPL). It will play a central role in the quest to identify that ‘first light’.”
“The 120m-euro (£95m; $150m) instrument, tucked inside its protective box, was loaded on to BA flight 217 for Washington Dulles International Airport. The reportedly smooth ride across the Atlantic took about 7.5 hours. On landing, Miri was set to be driven the relatively short distance around the US capital’s ‘Beltway’ to Goddard for an unpacking on Wednesday. NASA engineers will then integrate Miri into the telescope structure prior to further testing.”
“The main container carried the flags of all the European nations that have worked on the instrument and the signatures of its principal scientist, Prof Gillian Wright, and its project manager, John Thatcher from the Astrium space company. A message read simply, ‘First and best’.”
(Europe has a heavy involvement in the development JWST, whose entire future remains somewhat in doubt at this point. If/when it flies, Europe’s contribution will be an integral part of its success. -JCB)
Kepler telescope studies star superflares
NASA’s Kepler space telescope has provided fresh insight on the colossal explosions that can afflict some stars.
(A superflare would be associated with very large starspots - much larger than those on the Sun.)
“These enormous releases of magnetic energy - known as superflares - could damage the atmosphere of a nearby orbiting planet, putting at risk any lifeforms that might reside there. Fortunately, Kepler shows superflares to be much less frequent on slow-rotating stars like our Sun. The new observations are reported in the journal Nature.”
“Hiroyuki Maehara from Kyoto University, Japan, and colleagues have now reviewed the data to compile the best statistics yet on the frequency and size of superflares. Kepler saw a total of 365 superflares during an observation period lasting 120 days. The numbers confirm that very few (only 0.2%) Sun-like stars experience monster flares.”
Three Years of Kepler
On March 6, 2009 the Kepler Mission left Earth to begin its search for exoplanets far and wide. In the past three years, it has amassed 2,321 exoplanet candidates and confirmed 61 of them. Just a drop in the bucket compared to what’s out there.
This is raw video from the launch day three years ago. I think it captures the excitement of the whole project perfectly. Goosebump warning.
Let’s keep creating that feeling.
(by curleyco, HT to NASA on Twitter)
Next Space Telescope Must Survive 'Big Science' Questions
NASA’s newest space telescope project has stayed alive despite a ballooning price tag that now stands at $8.8 billion. But whether or not the James Webb Space Telescope survives into the future may depend upon how well it can maintain the broad political support that helped past “big science” projects ultimately prove successful.
(NASA engineer Ernie Wright looks on as the first six flight ready James Webb Space Telescope’s primary mirror segments are prepped to begin final cryogenic testing at NASA’s Marshall Space Flight Center. CREDIT: NASA/MSFC/David Higginbotham)
“One hopeful example comes from the Hubble Space Telescope that the James Webb Space Telescope is scheduled to replace. That telescope required $10 billion over two decades after early cost overruns and spacewalk repairs to fix a defective mirror in orbit, but still maintained strong support from both scientists and the U.S. Congress despite all of its troubles.”
“‘For big science on the scale of megaprojects, the support of scientists is necessary but the historical record argues it is not sufficient,’ said Robert Smith, a historian of science at the University of Alberta in Canada. ‘Big science raises big questions and strong support from outside of the scientific community is needed to sustain a megaproject over a long period.’”
“Not all ‘big science’ projects have been as lucky as Hubble. U.S. physicists once dreamed of building the Superconducting Super Collider, a huge particle accelerator in Texas that would have been bigger than the famed Large Hadron Collider in Switzerland. But the SSC project failed to become reality because its support never grew beyond a small community of scientists, Smith pointed out during the annual meeting of the American Association for the Advancement of Science in Vancouver on Feb. 18. Such support proved incapable of keeping SSC alive when the political winds shifted against it — even after $2 billion had already been spent.”
The example of the SSC in this story is a canny observation. It proves that Congress WILL walk away from billions already spent on a large science project if it becomes politically untenable. Even Texas, with its powerful pull on the national political stage, and its Congressional delegation were unable to save the SSC when the plug was pulled in the 80’s.
This issue barely touches on something that I think reveals a potentially fatal flaw in the attitude of the American astronomical community. Last summer, when the funding plug was initially pulled on JWST, the community’s reaction was largely (what it believed to be) righteous indignation, with calls for every astronomer to write their Congressional representatives demanding reinstatement of full funding. Form letters were provided for those not so adept at writing for political audiences. But the belief was just that ‘all we have to do is make enough noise’ and the unending tap of federal funding would be re-opened.
American astronomy is, I think, at a crossroads. Supply in the employment market far exceeds demands in terms of permanent positions, with jobs often eliminated after senior faculty retire. Such is the trend in federal funding, which has been effectively flat for many years. New Ph.D.’s are funneled into a sort of “holding tank” of postdoctoral positions, and those who stay in seem to be far more often on soft money and move from job to job. The real federal funding situation is likely to get increasingly dire with time, as America realizes its decades-long spending binge is dangerously unsustainable. And as I like to say, with limited resources to find science, if Americans are given a choice between, say, astronomy research and curing cancer, they’re going to pick cancer every time.
Our field needs a sea change in its “corporate culture”. It needs to slim down. It needs to graduate fewer new Ph.D.s, reducing pressure on the workforce that leads to exploitation of postdocs. If JWST is indeed canceled, the shock to the system will be palpable, and literally thousands of people will be out of work. We can no longer afford to act like this is the 80’s and we’re still awash in Cold War-related basic R&D spending. I’m afraid that if we don’t reform our field at a very fundamental level, we will soon be surpassed by the Europeans and then the Chinese, and the sun will set on the Golden Age of American Astronomy. (JCB)
Rare Black Hole Survives Galaxy's Destruction
(This spectacular edge-on galaxy, called ESO 243-49, is home to an intermediate-mass black hole that may have been stripped off of a cannibalized dwarf galaxy. CREDIT: NASA, ESA, and S. Farrell, Sydney Institute for Astronomy, University of Sydney)
“Like a fossil hinting at a long-gone animal, a black hole is offering clues about a now-destroyed galaxy that may once have existed around it.”
“The Hubble Space Telescope recently spied a cluster of young blue stars surrounding a rare mid-weight black hole that suggests the black hole was once at the center of a dwarf galaxy. Astronomers think this galaxy was torn apart by the gravity of a larger host galaxy that it orbited.”
“The violent encounter would have stripped away most of the dwarf galaxy’s stars, but it also could have compressed the gas around its central black hole, triggering a new wave of star formation. It is these new stars that Hubble recently saw signs of.”
Our Galaxy's Giant Black Hole May Munch on Asteroids
The gigantic black hole at the heart of our Milky Way galaxy may be devouring asteroids on a daily basis, a new study suggests.
(This image from NASA’s Chandra X-ray Observatory shows the center of our galaxy, which hosts a supermassive black hole known as Sagittarius A*. Chandra has detected X-ray flares about once a day from Sgr A*; they may result from the black hole gobbling up asteroids, as the artist’s concept on the right depicts. CREDIT: X-ray: NASA/CXC/MIT/F. Baganoff et al.; Illustrations: NASA/CXC/M.Weiss)
For several years, NASA’s Chandra spacecraft has detected X-ray flares about once a day coming from our galaxy’s central black hole, which is known as Sagittarius A* (Sgr A* for short). These flares may be caused by asteroids falling into the supermassive black hole’s maw, according to the study.
“People have had doubts about whether asteroids could form at all in the harsh environment near asupermassive black hole,” study lead author Kastytis Zubovas, of the University of Leicester in the United Kingdom, said in a statement. “It’s exciting because our study suggests that a huge number of them are needed to produce these flares.”
Zubovas and his colleagues suggest that a cloud around Sgr A* contains trillions of asteroids and comets that the black hole stripped from their parent stars.
Hubble Telescope Spies Milky Way Galaxy's Twin
(The barred spiral galaxy NGC 1073 is seen in this image from the Hubble Space Telescope. CREDIT: NASA & ESA )
“An uncanny twin of our own Milky Way galaxy takes center stage in a new cosmic portrait by the Hubble Space Telescope unveiled today (Feb. 3).”
“The amazing photo shows the galaxy NGC 1073, a barred spiral like our own Milky Way. The galaxy is located 55 million light-years away in the constellation of Cetus (The Sea Monster). By looking at cosmic wonders thought to be similar to our own galactic home, astronomers hope to learn more about the Milky Way, which we can only see from the inside.”
“The bars, made of dense lines of stars at the galaxies’ centers, are thought to form as gravity causes density waves that push gas inward, supplying material for new stars, Hubble mission researchers explained in a statement. This inflow of gas can also feed the hungry giant black holes thought to inhabit the centers of most such galaxies.”
As someone who has worked on this structural issue of spiral galaxies, I have to say that I disagree with the interpretation that NGC 1073 is the Milky Way’s “twin”. It’s true that the Milky Way seems to have a bar, like this galaxy, but it appears that the Milky Way’s bar is smaller in length compared to the overall size of the galaxy. The evidence suggests that not only is the MW’s bar smaller, but the spiral arms are more tightly wound around it than is evident in the HST picture of NGC 1073. Also, the ring of stars at the diameter of the bar isn’t nearly as pronounced in the MW. For a recent reference, see Bob Benjamin’s excellent conference proceedings article from Massive Star Formation: Observations Confront Theory, held in 2007. An artist’s conception based on recent evidence is shown below; credit: R. Hurt (SSC), JPL-Caltech, NASA. (-JCB)
An Evaporating Exoplanet?
(Artist rendering of an exoplanet atmosphere “evaporating” near its host star. Credit: ESA / Alfred Vidal-Madjar, Institut d’Astrophysique de Paris, CNRS, France)
“There’s something strange obscuring the light from a cool, low-mass star observed by NASA’s Kepler mission. Every 15.685 Earth days, KIC 12557548’s light dims for about 1.5 hours. The dips in starlight aren’t always the same — some events block more light than others — so the occultations don’t look like the regular blip caused by a planet passing in front of the star. After considering various options, an international team of astronomers reported recently that the signal might be from debris thrown off by a small rocky planet as it disintegrates under the star’s glare.”
“Astronomers found what looks like an evaporating gas giant in 2003, but if real KIC 12557548’s world would be the first solid exoplanet seen dematerializing.”
“Spectral observations may be able to determine if the planet and its tail are there and what the tail is made of. The astronomers put their bet on pyroxene, a silicate mineral found in Earth’s crust and mantle (and in meteorites) that should survive close proximity to KIC 12557548 long enough to block starlight before the grains vaporize.”
We’re getting close to making firm detections of Earth-like exoplanets, not only in terms of size, density, and other physical properties, but in their compositions. Astronomers are still novices in the business of understanding exoplanets’ detailed characteristics, and are not entirely sure what variety of possible planets exists. The detection of silicate minerals around an exoplanet host star would lend support to the idea that some of these extraterrestrial worlds are of a rather similar composition to our own home. The closer we come to finding planets like our own, the closer we may be to answering the ultimate question: do any of them harbor life? -JCB
Astronomy news, recent research results, and pretty pictures from the media along with context, commentary, and explanations for folks who dig this sort of thing. Written by a quasi-professional astronomer affiliated with the University of Texas at Austin.
