Category Archives: SETI

Video- “Astrochemistry: Putting the Astro in Astrobiology”

Alexander Tielens of the University of Leiden talks in this SETI Institute seminar about Astrochemistry: putting the astro in astrobiology.

The first half or so of the talk, which is suitable for a general audience, Tielens gives a overview of exoplanet discoveries, how planets are formed, and the basics of how life could have arisen on earth. In the rest of the talk, he goes into the details of the research into how the  chemical building blocks of early life could have been formed.

From the caption:

Astrobiology, the study of emergence of life and the its distribution in the Universe, addresses the most fundamental questions in science: “How does life begin ?” and “Are we alone ?” Over the last 20 years, we have discovered that planets are bountiful in the galaxy and that one in every five solar-type stars has a planet in the habitable zone. We have learned that extremophiles have spread to essential every niche – even the seemingly most inhospitable ones – on our planet. And we have learned that life started essentially as soon as conditions permitted, within some 200 million of the late heavy bombardment, or perhaps even earlier.

This has resulted in a paradigm shift from “Life on Earth is unique” to the premise “life is widespread”. As a result, searching for biosignatures in space has taken on a life by itself. In this talk, Dr. Tielens will summarize this shift in our thinking and the global processes that may have influenced the first steps towards life.

The focus in this talk will be on astrochemistry – the starting point of astrobiology – the chemical evolution that takes place in space where simple molecules are transformed into complex molecules and complex molecules are broken down to simple ones. This chemical dance of the elements produces a wide variety of organic compounds. I will review the processes that drive this chemical evolution in space, particularly in regions of star and planet formation.

The focus will be on understanding the raw materials that are delivered to newly formed planets and their relationship to the building blocks from which prebiotic material was formed and biological systems evolve.

Video: Direct imaging of extrasolar planets and the discovery of a young Jupiter

In this SETI Institute seminar, Bruce Macintosh of Stanford talks about the Direct imaging of extrasolar planets and the discovery of a young Jupiter 

From the caption:

Learn about an exciting new exoplanet discovery—a Jupiter-like planet called “51 Eri b” that orbits a star a 100 light years away in the constellation of Eridanus.

Using a powerful new imaging device, astronomers have spied a Jupiter-like exoplanet 100 light-years distant in the constellation of Eridanus. Unlike most planets found around other stars, 51 Eri b has been seen directly. The instrument employed to make the discovery has also made a spectroscopic analysis of the light reflected from the planet, and has detected gases similar to those in Jupiter’s atmosphere.

Because GPI not only images exoplanets but also spreads their light for chemical analysis, astronomers can search for such common gases as water and methane in their atmospheres. Researchers had expected to see methane in directly-imaged exoplanets based on the temperature and chemistry of these worlds, but had failed to detect these molecules in large quantities using earlier instruments. However, the observations of 51 Eri b made with GPI have clearly revealed a methane-dominated atmosphere similar to that of Jupiter.

An extraordinarily complex instrument the size of a small car, GPI is attached to one of the world’s biggest telescopes – the 8-meter Gemini South instrument in Chile. It began its survey of stars last year.

The host star, 51 Eri, is very young, a mere 20 million years old, and is slightly hotter than the Sun. The exoplanet 51 Eri b, whose mass is estimated to be roughly twice that of Jupiter, appears to orbit its host star at a distance 13 times greater than the Earth-Sun distance. If placed in our own solar system, 51 Eri b’s orbit would lie between those of Saturn and Neptune.

Video: Latest on occurrence rates of earth-like exoplanets

Here’s a SETI Institute seminar on using the Kepler space observatory data to determine how often earth-like exoplanets will be found around other stars: Planet Occurrence Rates with Kepler: Reaching Towards the Habitable Zone – SETI Institute

Dr. [Christopher Burke discusses the] latest results in measuring terrestrial planet occurrence rates using the planet candidates discovered by the Kepler pipeline.

For the first time an accurate model for the Kepler pipeline sensitivity to transiting planets is publicly available. Dr. Burke’s new analysis finds higher planet occurrence rates and a steeper increase in planet occurrence rates toward small planets than previously believed.

In addition, Dr. Burke will identify the leading sources of systematics that remain impacting Kepler planet occurrence rate determinations and approaches for minimizing their impact in future studies.

This work also sharpens our understanding on the dependence of planet occurrence rates on stellar effective temperature with potential implications for understanding the planet formation process.

Beyond the solar system: More on Breakthrough Initiative + Smallsat exoplanet finder + Fast radio burst mystery

Some misc. items on SETI and exoplanets:

The Planetary Society‘s Planetary Radio program recently webcast two programs about the  Breakthrough Initiative (see earlier post), which plans to spend $10M per year for the next ten years on a search for intelligent life beyond earth.

Ann Druyan and the Breakthrough SETI Initiatives

The Breakthrough Initiatives will pump $100 million into the Search for Extraterrestrial Intelligence in the next 10 years, vastly expanding humanity’s quest to learn if it has company in the universe. Among the leaders of this brave new project is Cosmos creator Ann Druyan. Join us for a special, extended conversation with Ann.

A New Era For SETI Research: More on the Breakthrough Initiatives

We follow last week’s conversation with Ann Druyan about the $100 million funding of the Search for Extraterrestrial Intelligence by visiting with two of the scientists who will do the work: Dan Werthimer of UC Berkeley and Karen O’Neil of the Green Bank Telescope.

Here’s an interesting article about the possibility of observing an earth sized planet in the Alpha Centauri system with a small telescope in space: Planet Hunters Bet Big on a Small Telescope to See Alien Earths – Lee Billings/Scientific American Blog Network –

According to Ruslan Belikov and Eduardo Bendek, two research scientists at NASA’s Ames Research Center in California, a 45-kilogram space telescope with a 30-to-45-centimeter mirror would be sufficient to deliver images of rocky planets in the habitable zones of either Alpha Centauri A or B. That’s smaller than some of the telescopes you can buy on Amazon.com, though you can’t purchase a planet-imaging space observatory off-the-shelf quite yet. Belikov, Bendek, and their collaborators call the concept ACESat – the Alpha Centauri Exoplanet Satellite – and have submitted it to NASA in response to the agency’s October 2014 call for proposals for Small Explorer missions, which have budgets capped at $175 million. If selected, the mission would be ready to launch no later than the end of 2020.

More about those odd fast radio bursts (FRBs) : Are aliens trying to contact us? Mathematical radio waves from deep space baffle scientists: Strange bursts of radio waves have a pattern that can’t be explained by known phenomenon – Mother Nature Network

The brevity of the bursts is particularly unusual because it means their source has to be extremely small, hundreds of kilometers across at most. And because they exhibit such a high pulse dispersion — a measure of the distance between the arrival of higher frequency waves within the signal compared to lower frequency waves — scientists believe they come from very far away, possibly another galaxy entirely.

All 10 of the bursts detected so far have dispersion measures that are multiples of a single number: 187.5. That’s the mathematical regularity that is hard to shake off. The breakdown of the pattern implies five sources for the bursts all at regularly spaced distances from Earth, billions of light-years away. Scientists have calculated this to be a five in 10,000 probability of a coincidence. In other words, not likely.

“If the pattern is real, it is very, very hard to explain,” said John Learned, a scientist at the University of Hawaii in Manoa who analyzed the FRBs.

Update: A comment about exoplanet naming: To Play or Not to Play the Exoplanet Name Game? – Lee Billings/Scientific American Blog Network