Tag Archives: Doppler Spectroscopy

NASA Space Place – Is Proxima Centauri’s ‘Earth-like’ Planet Actually Like Earth At All?

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in October, 2016.

By Dr. Ethan Siegel

2013february2_spaceplaceJust 25 years ago, scientists didn’t know if any stars—other than our own sun, of course—had planets orbiting around them. Yet they knew with certainty that gravity from massive planets caused the sun to move around our solar system’s center of mass. Therefore, they reasoned that other stars would have periodic changes to their motions if they, too, had planets.

This change in motion first led to the detection of planets around pulsars in 1991, thanks to the change in pulsar timing it caused. Then, finally, in 1995 the first exoplanet around a normal star, 51 Pegasi b, was discovered via the “stellar wobble” of its parent star. Since that time, over 3000 exoplanets have been confirmed, most of which were first discovered by NASA’s Kepler mission using the transit method. These transits only work if a solar system is fortuitously aligned to our perspective; nevertheless, we now know that planets—even rocky planets at the right distance for liquid water on their surface—are quite common in the Milky Way.

On August 24, 2016, scientists announced that the stellar wobble of Proxima Centauri, the closest star to our sun, indicated the existence of an exoplanet. At just 4.24 light years away, this planet orbits its red dwarf star in just 11 days, with a lower limit to its mass of just 1.3 Earths. If verified, this would bring the number of Earth-like planets found in their star’s habitable zones up to 22, with ‘Proxima b‘ being the closest one. Just based on what we’ve seen so far, if this planet is real and has 130 percent the mass of Earth, we can already infer the following:

* It receives 70 percent of the sunlight incident on Earth, giving it the right temperature for liquid water on its surface, assuming an Earth-like atmosphere.

* It should have a radius approximately 10 percent larger than our own planet’s, assuming it is made of similar elements.

* It is plausible that the planet would be tidally locked to its star, implying a permanent ‘light side’ and a permanent ‘dark side’.

* And if so, then seasons on this world are determined by the orbit’s ellipticity, not by axial tilt.

Yet the unknowns are tremendous. Proxima Centauri emits considerably less ultraviolet light than a star like the sun; can life begin without that? Solar flares and winds are much greater around this world; have they stripped away the atmosphere entirely? Is the far side permanently frozen, or do winds allow possible life there? Is the near side baked and barren, leaving only the ‘ring’ at the edge potentially habitable?

Proxima b is a vastly different world from Earth, and could range anywhere from actually inhabited to completely unsuitable for any form of life. As 30m-class telescopes and the next generation of space observatories come online, we just may find out!

Looking to teach kids about exoplanet discovery? NASA Space Place explains stellar wobble and how this phenomenon can help scientists find exoplanets: spaceplace.nasa.gov/barycenter/en/

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.


Caption: An artist’s conception of the exoplanet Kepler-452b (R), a possible candidate for Earth 2.0, as compared with Earth (L). Image credit: NASA/Ames/JPL-Caltech/T. Pyle.

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

NASA News Digest: Space Science For 9 March – 29 March 2016

Greetings fellow astrophiles,

The NASA News Service provides up-to-date announcements of NASA policy, news events, and space science. A recent selection of space science articles are provided below, including direct links to the full announcements. Those interested in receiving these announcements from NASA can subscribe to their service by sending an email to: hqnews-request@newsletters.nasa.gov?subject=subscribe

NASA Targets May 2018 Launch of Mars InSight Mission

RELEASE 16-026 (Click here for the full article) – 9 March 2016

2016march31__16_026NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission to study the deep interior of Mars is targeting a new launch window that begins May 5, 2018, with a Mars landing scheduled for Nov. 26, 2018.

InSight’s primary goal is to help us understand how rocky planets – including Earth – formed and evolved. The spacecraft had been on track to launch this month until a vacuum leak in its prime science instrument prompted NASA in December to suspend preparations for launch.

InSight project managers recently briefed officials at NASA and France’s space agency, Centre National d’Études Spatiales (CNES), on a path forward; the proposed plan to redesign the science instrument was accepted in support of a 2018 launch.

For addition information about the mission, visit: www.nasa.gov/insight

More information about NASA’s journey to Mars is available online at: www.nasa.gov/journeytomars

NASA Announces Dates for One of World’s Largest Hackathons

RELEASE 16-034 (Click here for the full article) – 23 March 2016

2016march31_space-apps-challenge2NASA’s open innovation incubator, the International Space Apps Challenge, will take place April 22-24. The global main stage for this year’s event will be in Pasadena, California, with local events taking place simultaneously in 193 locations spanning 72 countries.

On April 23 and 24, participants are asked to develop mobile applications, software, hardware, data visualizations and platform solutions that could contribute to space exploration missions and help improve life on Earth.

This year’s challenge will include a Data Bootcamp on April 22, streamed live from the global main stage. The bootcamp is open to the public and will give participants the opportunity to learn new skills with computer coding and data.

“We’re reaching out to women’s organizations influential in the data and maker communities to participate, and we encourage women-led teams in the hackathon,” said Deborah Diaz, chief technology officer for information technology.

A more information about the Space Apps Challenge, and a full list of NASA challenges, go to: spaceappschallenge.org

Follow the challenge on Twitter at: twitter.com/spaceapps

NASA Gets Down to Earth This Year With Globe-Spanning Expeditions

RELEASE 16-039 (Click here for the full article) – 23 March 2016

NASA is sending scientists around the world in 2016 – from the edge of the Greenland ice sheet to the coral reefs of the South Pacific – to delve into challenging questions about how our planet is changing and what impacts humans are having on it.

While Earth science field experiments are nothing new for NASA, the next six months will be a particularly active period with eight major new campaigns taking researchers around the world on a wide range of science investigations. The public is invited to follow this journey of exploration online through NASA’s social media channels and the new Earth Expeditions webpage, which will feature regular video, photos and blog posts from these missions and other ongoing field activities.

“Combining the long-term global view from space with detailed measurements from field experiments is a powerful way of deciphering what’s happening in our world,” said Michael Freilich, director of NASA’s Earth Science Division in Washington. “Scientists worldwide use NASA Earth science field data together with satellite data and computer models to tackle many of today’s environmental challenges and advance our knowledge of how the Earth works as a complex, integrated system.”

To follow all the NASA Earth Expeditions, visit: www.nasa.gov/earthexpeditions

NASA Selects Instrument Team to Build Next-Gen Planet Hunter

RELEASE 16-038 (Click here for the full article) – 29 March 2016

2016march31_16-038_0NASA has selected a team to build a new, cutting-edge instrument that will detect planets outside our solar system, known as exoplanets, by measuring the miniscule “wobbling” of stars. The instrument will be the centerpiece of a new partnership with the National Science Foundation (NSF) called the NASA-NSF Exoplanet Observational Research program, or NN-EXPLORE.

The instrument, named NEID (pronounced “nee-id”), which is short for NN-EXPLORE Exoplanet Investigations with Doppler Spectroscopy, will measure the tiny back-and-forth wobble of a star caused by the gravitational tug of a planet in orbit around it. The wobble tells scientists there is a planet orbiting the star, and the size of the wobble indicates how massive the planet is.

The highly precise instrument, to be built by a Pennsylvania State University research group led by Dr. Suvrath Mahadevan, will be completed in 2019 and installed on the 3.5-meter WIYN telescope at the Kitt Peak National Observatory in Arizona.

For more information, visit: exep.jpl.nasa.gov/NNExplore/

NASA’s ‘Spaceport of the Future’ Reaches Another Milestone

RELEASE 16-037 (Click here for the full article) – 29 March 2016

2016mar31_16-037NASA has completed a major milestone on its journey to Mars and is ready to begin another phase of work on its spaceport of the future, where the next generation of astronauts will launch to Mars and other deep-space destinations.

The agency recently wrapped up a comprehensive and successful review of plans for the facilities and ground support systems that will process the agency’s Space Launch System (SLS) rocket and Orion spacecraft at NASA’s Kennedy Space Center in Florida.

“NASA is developing and modernizing the ground systems at Kennedy to safely integrate Orion with SLS, move the vehicle to the pad, and successfully launch it into space,” said Bill Hill, deputy associate administrator of NASA’s Exploration Systems Development Division at the agency’s Headquarters in Washington. “Modernizing the ground systems for our journey to Mars also ensures long-term sustainability and affordability to meet future needs of the multi-use spaceport.”

For more information on GSDO, visit: www.nasa.gov/groundsystems

For more information on Orion, visit: www.nasa.gov/orion