Artist rendering of the Directed Energy Interstellar Study.
Credits: P. Lubin

A second day of provocative presentations is underway today at Breakthrough Discuss 2017, an event being held at Stanford University.

The second and final day will assess the significance of the newly discovered exoplanets for the long-term Breakthrough Starshot endeavor, a program spearheaded by Yuri Milner to develop a practical interstellar space probe.

According to a press statement from Breakthrough Discuss, highlights of speakers yesterday described the state of the art in observations of planets around nearby stars.

Swarm of laser-sail spacecraft leaving the solar system.
Credit: Adrian Mann

Promising targets

Obtaining pictures of planets is difficult, and most are found using indirect methods. These methods have shown that most stars have planets in short-period orbits, and since most stars in the galaxy are red dwarfs, these provide promising targets when searching for habitable worlds.

Many planets around these stars have recently been reported, including Proxima Centauri b, and LHS 1140 b and the TRAPPIST-1 system.

NASA’s Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star.This artist’s concept allows us to imagine what it would be like to stand on the surface of the exoplanet TRAPPIST-1f, located in the TRAPPIST-1 system in the constellation Aquarius.credit:
Credit: NASA/JPL-Caltech

Although red dwarfs have high X-ray and UV radiation, and planets around them are more likely to be tidally locked (one side always in fierce daylight and the other in cold night), they are long-lived stars, potentially allowing plenty of time for life to arise.

Living colors

The difficulty of imaging planets even around nearby stars is compounded when trying to measure their colors to find indications of life.

But telescopes that will come online in the mid-2020s will have the capability to detect “biosignatures” in exoplanet atmospheres. By looking for signatures of oxygen and methane, that are naturally destroyed over time if not replenished by such processes as living organisms, perhaps in the next 10 to 15 years we will have found another world where humans could breathe.

New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO., left, Johns Hopkins University Applied Physics Laboratory (APL) Director Ralph Semmel, center, and New Horizons Co-Investigator Will Grundy Lowell Observatory hold a print of an U.S. stamp with their suggested update since the New Horizons spacecraft explored Pluto in July 2015. Credit: (NASA/Bill Ingalls)

It was noted that 70 years of observations of Pluto saw it simply as a point of light, until the New Horizons probe yielded in-situ measurements of Pluto as a world in its own right. Therefore, what on-the-spot observations of habitable zone planets around nearby M-dwarfs might be possible in 70 years’ time?

Sounds of silence

The findings from the first year of Breakthrough Listen observations of around 700 nearby stars, placing sensitive limits on the presence of engineered emission from these targets was noted.

Green Bank Telescope (GBT) has joined in the search, receiving roughly $2 million per year for 5 years. The 100-meter GBT is the world’s largest fully steerable radio telescope, located in West Virginia.
Credit: NSF

Although no convincing signs of extraterrestrial intelligence have yet been found, the speakers and audience expressed optimism and enthusiasm for what would be possible with the next generation of searches.

Starshot

As the closest known exoplanet, Proxima b is the current primary target for Starshot, which aims to develop the technology to send gram-scale spacecraft travelling at 20 percent of the speed of light to Alpha Centauri, some 4.367 light-years away.

Credit: Breakthrough Initiatives

Starshot mission leaders Avi Loeb, Philip Lubin and Zac Manchester are among the distinguished participants at today’s Breakthrough Discuss.

Breakthrough Initiatives are a suite of scientific and technological programs exploring the big questions around life in the universe, such as: Are we alone? What are the nearest habitable planets? And can we become an interstellar civilization?

 

Resources

The conference today, Friday, April 21, will be broadcast on Facebook Live at:

http://www.Facebook.com/BreakthroughPrize

Viewers are encouraged to join in the conversation and submit questions, which have the opportunity to be answered by the panelists in real-time.

Start times for all sessions will also be posted on the Breakthrough Facebook page.

For more information on the program, including a detailed schedule, please visit:

https://breakthroughinitiatives.org/Events

For detailed information on Breakthrough Initiatives, go to:

https://breakthroughinitiatives.org

Special thanks to Kayla Engebretsen for information used in this article.

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