This spooky-tinged multiplicity of planet Earths comes especially for Halloween, as observed through the various spectral bands of the Hera asteroid mission’s HyperScout H instrument out in deep space.
Hera’s HyperScout H is a hyperspectral imager that observes its targets in more colours than the human eye can distinguish, across 25 spectral bands from the visible to near infrared 650–950 nm wavelength spectral range. These close-up images of Earth were produced by separating these wavelengths to show how the instrument operates in practice, as observed on 11 October 11 between 01:59 to 18:09 UTC.
The false colour images are visualised using the TwilightShifted palette: a colour map ranging across bluish black through purplish white into reddish black to represent light intensity levels.
“This allows us to observe cloud patterns on our planet from a distance of nearly 2 000 000 km away and to test the sharpness of our data processing algorithms,” says instrument team member Marcel Popescu of the University of Craiova in Romania. “To quote Carl Sagan, all our lives are contained within these few pixels.”
Following a successful launch on 7 October 2024, Hera’s instruments were switched on for the first time as part of the spacecraft’s ongoing Near-Earth Commissioning Phase.
On Thursday 10 October and Friday 11 October, Hera’s topside Asteroid Deck, which houses the spacecraft’s instruments, was pointed back towards our planet so that its instruments could capture their first images of Earth and the Moon from a distance of more than one million km away.
“Once Hera reaches the Dimorphos asteroid HyperScout H will prospect its mineral make-up,” explains instrument principal investigator Julia de León of Instituto de Astrofísica de Canarias. “This first calibration test was an exciting experience, which showed that both the instrument and its data processing chain are working well.”
The shoebox-sized HyperScout H is the latest in a family of HyperScout imagers previously flown in terrestrial orbit for Earth observation, produced by cosine Remote Sensing in the Netherlands with ESA support.
Next March HyperScout H will also be among the Hera instruments trained on Mars and martian moon Deimos as the mission performs a swingby of the red planet.
Marco Esposito, cosine Remote Sensing’s Managing Director, comments: “It is fantastic to have the Earth-Moon system as our first target, observing this unique relationship and capturing it spectrally as we move swiftly toward Mars.”
Hera is ESA’s first planetary defence mission, on its way to visit the first asteroid to have had its orbit altered by human action. By gathering close-up data about the Dimorphos asteroid, which was impacted by NASA’s DART spacecraft in 2022, Hera will help turn asteroid deflection into a well understood and potentially repeatable technique.
prepared by the HyperScout-H team: Julia de León, George Prodan, Björn Grieger, Gábor Kovács, Marcel Popescu.
The Hera mission wishes you a Happy Heraween!