The Mission

       To take the first picture of an earth-like planet in the Alpha Centauri star system

A simulation of the next pale blue dot

A simulation of the next pale blue dot

And why that cerulean color? The blue comes partly from the sea, partly from the sky. While water in a glass is transparent, it absorbs slightly more red light than blue. If you have tens of meters of the stuff or more, the red light is absorbed out and what gets reflected back to space is mainly blue. In the same way, a short line of sight through air seems perfectly transparent. Nevertheless – something Leonardo da Vinci excelled at portraying – the more distant the object, the bluer it seems. Why? Because the air scatters blue light around much better than it does red. So the bluish cast of this dot comes from its thick but transparent atmosphere and its deep oceans of liquid water.
— Carl Sagan, in “Pale Blue Dot – A Vision of the Human Future in Space"

Project Overview

Project Blue will build and launch a compact space telescope with a 45-50 centimeter aperture to directly image the habitable zones of the nearest Sun-like stars to Earth – Alpha Centauri A and B – with the goal of revealing the closest potentially habitable planet beyond our Solar System. Project Blue aims to image “Earth-like” planets (roughly 0.5 to 1.5 times of the size of Earth) orbiting within either star's habitable zone and possessing an atmosphere that could allow liquid water to exist on its surface. If such a planet were to be similar to the Earth, with oceans and such an atmosphere, we might just “see blue”.

If such planets orbit around Alpha Centauri A and B — and there are two Sun-like stars to investigate — our mission will be the first to take a direct image of another Earth, or “pale blue dot” as Carl Sagan put it, generating the most detailed image of an inner planetary system around any star other than our Sun. Such a discovery will profoundly impact our understanding of the potential for life to exist elsewhere in our galaxy, spur public interest in astronomy and science, and accelerate the search for other potentially habitable worlds.

Science Objective

Directly detect and characterize Earth-like planets in the aCen A&B system. 

Science Impact

We aim to provide the scientific community with an instrument capable of investigating the Alpha Centauri system within about 3 years. Any planets Project Blue finds will be excellent potential targets for future large space telescopes being developed by NASA and other space agencies. In particular, if any potentially habitable planets are found, there will be a substantial surge of interest to apply spectroscopic techniques to discern details about the nature of the planets and their atmospheres.

Project Blue will demonstrate and test coronagraph and wavefront technologies similar to ones that could be used on much larger future space telescopes currently being studied by NASA (e.g., HabEX, LUVOIR), and thus help to retire technical risks and hone the observing techniques and data processing algorithms for those missions.

The Technology

Project Blue will place a state-of-the-art exoplanet imaging telescope into orbit. The instrument will be equipped with advanced high contrast imaging technologies embedded in a coronagraph with a deformable mirror, multi-star wavefront control, and specialized post-processing techniques. Together they can efficiently suppress the light from both stars (Alpha Centauri A and B) separately, thus allowing any planets to be seen. Our team has extensive experience developing and testing these technologies — now it’s time to get them into space!

Why Alpha Centauri?

Quite simply, we believe Alpha Centauri is the best target for direct imaging an Earth-like planet in coming years.

  • Alpha Centauri is our closest neighboring solar system at only 4.37 light years away. The close proximity allows us to design a small telescope and keep the mission cost down, making our mission more affordable than a project that would use similar technology to conduct a survey of star systems further away.
  • Alpha Centauri has two stars (Alpha Cen A and B) similar to our Sun in size, brightness and temperature. This is an incredible opportunity for the Project Blue mission because it increases the likelihood of discovering a planet in a habitable zone.
  • Alpha Centauri is the focus of many research efforts because of its proximity to Earth. The quest to detect planets around the Alpha Centauri stars has been ongoing and spans the entire range of detection methods including ‘wobble’ (radial velocities, astrometry), photometric and direct imaging techniques. Project Blue is unique in pursuing a dedicated coronagraphic space telescope mission, but is one of numerous efforts seeking to improve on past attempts.
  • A small, rocky planet was recently discovered in the habitable zone around Proxima Centauri, called Proxima b. Proxima Centauri is the third star in the Alpha Centauri system, though it is much smaller than Alpha Cen A or B. The exoplanet Proxima b was detected indirectly; scientists measured a small ‘wobble’ in the motion of the star due to the gravity of the planet in its orbit. Although Proxima b orbits in the habitable zone of its parent star, the star is such a small, dim star (called a red dwarf) its habitable zone and Proxima b’s orbit are incredibly close — nine times closer than Mercury is to our Sun. This is why Project Blue is not trying to image Proxima b. It would take a much larger telescope to resolve the star from the planet, and not even the largest space telescopes being planned could do so in visible light. But the good news is that we now know that there’s a terrestrial-class planet orbiting one of the stars in the Alpha Centauri system. This makes us optimistic that there could be other rocky planets orbiting Alpha Cen A and B.


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