An instrument that NASA is developing for detecting Earth-like planets in other solar systems and can study the atmosphere for chemical signatures has come another step closer to becoming a reality, the NASA/Goddard Space Flight Center said on 12 November.

The instrument, Visible Nulling Coronagraph (VNC),  on testing has been found to be able to detect nearly billion-to-one contrast, but over a narrow band in the visible spectrum, NASA says.

"This achievement", Rick Lyon, scientist at NASA, said, "was made possible by engineers Udayan Mallik, who set up all computer interfacing to control the devices, and Pete Petrone, who built the VNC hardware and optics."

The VNC combines an interferometer, an instrument that extracts information about waves, with a coronagraph - a special telescope which can block direct light from stars so that objects hidden by the star's glare become visible – for the first time.

Brian Hicks, a fellow with NASA's Postdoctoral Program who is working with VNC Principal Investigators Rick Lyon and Mark Clampin, who are scientists at NASA's Goddard Space Flight Center in Greenbelt, Maryland said, "It's well on its way to demonstrating operations over a broader spectral range, including the ultraviolet, visible, and near-infrared bands."

The VNC's importance, Hicks said, lies in future astrophysics missions when operations to characterize exoplanets will be undertaken.

"The VNC is demonstrating the spectral range needed for planet characterization. It will be more sensitive for finding fainter planets. It also will enable spectroscopy, which is what NASA will need to study the atmospheres of exoplanets to identify signatures of water, oxygen, carbon dioxide, methane, and ozone - the chemistry we associate with habitability for life as we know it", Eurekalert reported Hicks as saying. 

He further added, "The goal is to use the improvements and the enabling technologies to make the VNC an even better choice for yielding the greatest science return."