Interstellar Space Molecules That Help Form Basic Life Structures Identified

Using various telescopes in La Palma (including the Telescopio Nazionale Galileo) and Texas, IAC researchers have detected the presence of naphthalene in the interstellar medium in the direction of the star Cernis 52 in the constellation Perseus. This molecule consists of two hexagonal rings of carbon atoms surrounded by hydrogen atoms. (Credit: Sources: Miguel Briganti (IAC), Digital Sky Survey, David Barrado. Credits: Gabriel Pérez, Multimedia Service/IAC)

A team of scientists led by researchers from the Instituto Astrofísica de Canarias (IAC) has succeeded in identifying naphthalene, one of the most complex molecules yet discovered in the interstellar medium. The detection of this molecule suggests that a large number of the key components in prebiotic terrestrial chemistry could have been present in the interstellar matter from which the Solar System was formed.

IAC researchers Susana Iglesias Groth, Arturo Manchado and Aníbal García, in collaboration with Jonay González (Paris Observatory) and David Lambert (University of Texas) have just published these results in Astrophysical Journal Letters.

The naphthalene was discovered in a star formation region in the constellation Perseus, in the direction of the star Cernis 52. “We have detected the presence of the naphthalene cation in a cloud of interstellar matter located 700 lightyears from the Earth”, says IAC researcher Susana Iglesias Groth. The spectral bands found in this consstellation coincide with laboratory measurements of the naphthalene cation.

Iglesias Groth further adds, “we aim to investigate whether other, more complex, hydrocarbons exist in the same region, including aminoacids”. When subjected to ultraviolet radiation and combined with water and ammonium, both very abundant in the interstellar medium, naphthalene reacts and is capable of producing a wide variety of aminoacids and naphthaloquinones, precursor molecules to vitamins.

All these molecules play a fundamental role in the development of life as we know it on Earth. In fact, naphthalene has been found in meteorites that continue to fall to the surface of the Earth, and which fell with much greater intensity in epochs preceding the appearance of life.

The work of these researchers also enables us to understand one of the most intriguing problems in interstellar medium spectroscopy. For the past 80 years, the existence has been known of hundreds of spectroscopic bands (the so-called “diffuse bands”) associated with interstellar matter, but the identification of the agent causing them has remained a mystery.

“Our results show that polycyclic aromatic hydrocarbons such as naphthalene are responsible for the diffuse bands and should be present throughout the interstellar medium”, says Iglesias Groth.

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Astrophysicists 'Weigh' Galaxy's Most Massive Star

Astrophysicists successfully "weighed" a star of a binary system with a mass 116 times greater than that of the Sun. Located in the massive star cluster NGC 3603, the supermassive star system, known under the name of A1, has a rotation period of 3.77 days. (Credit: CRAQ)

Theoretical models of stellar formation propose the existence of very massive stars that can attain up to 150 times the mass of our Sun.

Until very recently, however, no scientist had discovered a star of more than 83 solar masses. Now an international team of astrophysicists, led by Université de Montréal researchers from the Centre de recherche en astrophysique du Québec (CRAQ), has found and "weighed" the most massive star to date.

Olivier Schnurr, Jules Casoli and André-Nicolas Chené, all graduates of the Université de Montréal, and professors Anthony F. J. Moffat and Nicole St-Louis, successfully "weighed" a star of a binary system with a mass 116 times greater than that of the Sun, waltzing with a companion of 89 solar masses, doubly beating the previous record and breaking the symbolic barrier of 100 solar masses for the first time.

Located in the massive star cluster NGC 3603, the supermassive star system, known under the name of A1, has a rotation period of 3.77 days. The masses were calculated by a combination of observations made with the SINFONI instrument, an integral field spectrograph operating on the Very Large Telescope on the site of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) in Chile, and infrared images coming from the Hubble Space Telescope.

The stars forming the A1 system are so massive and bright that the light they transmit shows characteristics that only "Wolf-Rayet" stars possess. A Wolf-Rayet star is a hot, massive and evolved star exhibiting a very high loss of mass due to a strong stellar wind (similar to the solar wind). Within the context of this work, a binary system transmitting X-rays at a power almost never seen in our Galaxy was also discovered near NGC 3603-A1.

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How many planets are there in our solar system anyway?

A. Feild / STScI / NASA / ESA

An artist's conception shows the dwarf planet Haumea and its two moons, Hi'iaka and Namaka.

So just how many planets are there in our solar system anyway? Eight? Nine? Thirteen? Or thousands? Far from settling the question, the "Great Planet Debate" has revealed just how complex and interesting the question is.

The planethood question got more interesting this week with the naming of yet another dwarf planet, Haumea. It's traditional to name planets after mythological deities - and Haumea, the Hawaiian goddess of childbirth and fertility, follows that formula.

The football-shaped world was found by Caltech astronomer Michael Brown just after Christmas 2004 (which prompted its initial, unofficial nickname: "Santa"). Haumea's discovery was shrouded in a scientific controversy that Brown recaps in his Weblog. At the time, controversy surrounded its planetary status as well, because it added to a growing class of objects in the same general class as Pluto. Astronomers surmised that hundreds of Pluto-scale objects may lurk on the icy rim of the solar system's disk, known as the Kuiper Belt.

The controversy came to a head in 2005 when Brown's team found the object now known as Eris - a world like Pluto, only bigger and farther out. All this led the International Astronomical Union to agonize over where to draw the line on planethood. In 2006, the IAU came up with a definition aimed at putting the solar system's eight biggest planets in one class, and Pluto in a different class with Eris and other dwarf planets or "plutoids."

The Great Planet Debate has been simmering ever since. In August, astronomers held a teach-in on the subject at Johns Hopkins University's Applied Physics Laboratory, which is the base of operations for NASA's New Horizons mission to Pluto. One of the purposes of the meeting was to see how teachers were handling the planethood question.

Scientist (and parent) sees 'teaching moment'
The education angle literally hit home for planetary scientist Alan Stern - and not just because he's the principal scientific investigator for New Horizons.

"My own son was told by a teacher that an answer was wrong on a test about Pluto," Stern told me last week. According to the test, the "right" answer for the number of planets in the solar system was eight - but Stern said that August's installment of the Great Planet Debate proved that the question was still up for grabs, even among educators.

"It was clear at the end of the two and a half days that there was no consensus," he said. "We're in transition. I think that's a teaching moment."

Stern has long argued that the IAU's definition of planethood provided more confusion than clarification. "There's a lot of unhappiness with the IAU's solution," he said. "I didn't hear anybody say, 'Oh, I think it's the cat's meow.'"

He maintains that it's wrong to think about the solar system as if there were a sharp division between eight planets and everything else. Even dwarf planets are still planets - and in Stern's mind, they may be more representative of the planetary spectrum than the eight biggies.

"It's the most populous class of planets in the solar system," Stern said. "Pluto's no longer the misfit."

There's something about Haumea
The fact that the IAU is giving names to dwarf planets - Pluto, Eris, Ceres, Makemake and now Haumea - shouldn't make a difference in the debate, Stern said. In fact, it totally makes sense. "From our perspective, these are planets. They deserve names," he said.

Stern has often compared the definition of planets with the definition of rivers: Sure, there might be six great rivers in the world ... or are there 14? In any case, that doesn't mean you have to set the Maquoketa River or thousands of other streams apart as "dwarf rivers." Every river, great or small, has its own special appeal - and it's the same with planets.

In fact, Haumea may be one of the most endearing little planets out there: Caltech's Brown has said it's his "favorite object in the solar system," in part because of its fast, end-over-end spin, the elongated shape it has as a result, and also because of its tightly orbiting satellites (which have been named Hi'iaka and Namaka, after two of the goddess Haumea's children). Brown said additional bits of ice and rock were apparently struck off Haumea in a cosmic collision long ago and are now circling the sun in their own orbits.

New Horizons gets a transplant ... and Twitter!
Oodles of such oddities may well come to light when the New Horizons spacecraft makes its way through the Kuiper Belt, starting in seven years. Last week, the probe underwent a successful "brain transplant" that upgraded the onboard software. It's now more than a billion miles from Earth, flying toward Pluto at a rate of about a million miles a day.

You can keep up with the mission's progress via Twitter or Facebook. (In the wake of Phoenix Mars Lander's Twitter success, it seems as if every space mission nowadays is getting into social networking.)

New Horizons' team will be checking out the spacecraft's instruments over the next couple of months, and then put the probe back to sleep for another months-long nap. The first "dress rehearsal" for the Pluto flyby will be conducted next year, but there's still a long way to go before showtime in 2015.

Will the planethood debate be settled by that time? Stern won't be surprised if it isn't. After all, it took decades for scientists to settle the controversy over continental drift - and some are still going back and forth over the implications of climate change and evolutionary biology.

"This is not atypical," Stern said. "It's just one of the most visible topics on the table right now."

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