If a space probe detected microbial life on another planet, would scientists know it when they saw it?
Identifying bacteria by sight is challenging enough on Earth, even for experts. To the naked eye, bacteria look like featureless blobs — not unlike the mineral grains that might surround them in a sample.
A form of holographic imaging could help. A new paper in the journal Astrobiology highlights a detection method called digital holographic microscopy, which uses laser light to capture 3-D images. Whereas standard microscopes can only view a thin slice of a drop of water, this method adds more depth.
The paper was co-authored by Chris Lindensmith of NASA’s Jet Propulsion Laboratory, Pasadena, California; Jay Nadeau of Caltech; and Manuel Bedrossian, a Caltech graduate student.