Due to launch in the early 2030s, NASA’s DAVINCI mission will investigate whether Venus — a sweltering world wrapped in an atmosphere of noxious gases — once had oceans and continents like Earth.
Consisting of a flyby spacecraft and descent probe, DAVINCI will focus
on a mountainous region called Alpha Regio, a possible ancient continent.
Though a handful of international spacecraft plunged through Venus’ atmosphere
between 1970 and 1985, DAVINCI’s probe will be the first to capture images of
this intriguing terrain ever taken from below Venus’ thick and opaque clouds.
But how does a team prepare for a mission to a planet that hasn’t seen
an atmospheric probe in nearly 50 years, and that tends to crush or melt its
spacecraft visitors?
Scientists leading the DAVINCI mission started by using modern data-analysis techniques to pore
over decades-old data from previous Venus missions. Their goal is to arrive at
our neighboring planet with as much detail as possible. This will allow
scientists to most effectively use the probe’s descent time to collect new
information that can help answer longstanding questions about Venus’
evolutionary path and why it diverged drastically from Earth’s.
On the left, a new and more detailed view of Venus’
Alpha Regio region developed by scientists on NASA's DAVINCI mission to Venus,
due to launch in the early 2030s. On the right is a less detailed map created
using radar altimeter data collected by NASA’s Magellan spacecraft in the early
1990s. The colors on the maps depict topography, with dark blues identifying
low elevations and browns identifying high elevations. To make the map on the
left, the DAVINCI science team re-analyzed Magellan data and supplemented it
with radar images collected on three occasions from the Arecibo Observatory in
Puerto Rico by scientists from Cornell University and the Smithsonian. DAVINCI
scientists then used machine-vision computer models to scrutinize the data and
fill in gaps in information. The red ellipses on each image mark the area
DAVINCI’s probe will descend over as it collects data on its way toward the
surface.
Jim Garvin/NASA's Goddard Space Flight Center
Between 1990 and 1994, NASA’s
Magellan spacecraft used radar imaging and altimetry to map the topography of
Alpha Regio from Venus’ orbit. Recently, NASA’s DAVINICI’s team sought more
detail from these maps, so scientists applied new techniques to analyze
Magellan’s radar altimeter data. They then supplemented this data with radar
images taken on three occasions from the former Arecibo Observatory in Puerto
Rico and used machine vision computer models to scrutinize the data and fill in
gaps in information at new scales (less than 0.6 miles, or 1
kilometer).
As a result, scientists improved
the resolution of Alpha Regio maps tenfold, predicting new geologic patterns on
the surface and prompting questions about how these patterns could have formed
in Alpha Regio's mountains.
Benefits of Looking Backward
Old data offers many benefits to
new missions, including information about what frequencies, parts of spectrum,
or particle sizes earlier instruments covered so that new instruments can fill
in the gaps.
At NASA
Space Science Data Coordinated Archive, which is managed out of NASA’s Goddard Space Flight
Center in Greenbelt, Maryland, staff restore and digitize data from old
spacecraft. That vintage data, when compared with modern observations, can show
how a planet changes over time, and can even lead to new discoveries long after
missions end. Thanks to new looks at Magellan observations, for instance, scientists recently found evidence of modern-day volcanic activity on
Venus.
Magellan was among the first
missions to be digitally archived in NASA’s publicly accessible online repository of planetary mission data. But the agency has
reams of data — much of it not yet digitized — dating back to 1958, when the
U.S. launched its first satellite, Explorer 1.
Data restoration is a complex and
resource-intensive job, and NASA prioritizes digitizing data that scientists
need. With three forthcoming missions to Venus — NASA’s DAVINCI and VERITAS,
plus ESA’s (European Space Agency) Envision — space data archive staff are
helping scientists access data from Pioneer Venus, NASA’s last mission to drop
probes into Venus’ atmosphere in 1978.
Mosaic of Venus
Alpha Regio is one of the most
mysterious spots on Venus. Its terrain, known as “tessera,” is similar in
appearance to rugged Earth mountains, but more irregular and disorderly.
So called because they resemble a
geometric parquet floor pattern, tesserae have been found only on Venus, and
DAVINCI will be the first mission to explore such terrain in detail and to map
its topography.
DAVINCI’s probe will begin photographing Alpha Regio — collecting the highest-resolution images yet — once it descends below the planet’s clouds, starting at about 25 miles, or 40 kilometers, altitude. But even there, gases in the atmosphere scatter light, as does the surface, such that these images will appear blurred.
Could Venus once have been a habitable world with
liquid water oceans — like Earth? This is one of the many mysteries associated
with our shrouded sister world. Credit: NASA's Goddard Space Flight Center
DAVINCI scientists are working on a
solution. Recently, scientists re-analyzed old Venus imaging data using a
new artificial-intelligence technique that can sharpen the images and use them
to compute three-dimensional topographic maps. This technique ultimately will
help the team optimize DAVINCI’s images and maps of Alpha Regio’s
mountains. The upgraded images will give scientists the most detailed view
ever — down to a resolution of 3 feet, or nearly 1 meter, per pixel — possibly
allowing them to detect small features such as rocks, rivers, and gullies for
the first time in history.
“All this old mission data is part
of a mosaic that tells the story of Venus,” said Jim Garvin, DAVINCI principal investigator and chief scientist at NASA Goddard. “A
story that is a masterpiece in the making but incomplete.”
By analyzing the surface texture and rock types at Alpha Regio, scientists hope to determine if Venusian tesserae formed through the same processes that create mountains and certain volcanoes on Earth.
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