Right now the eyes of the world are firmly focused on Mars. NASA’s Perseverance rover
is finding organic molecules in ancient sediment in its hunt for life, and Elon Musk is planning
to land humans on the Red Planet within the next five years or so. But, very soon, our
focus will shift to Venus.
This scalding hot vision of hell has been enticing us for years with glimpses of possible
life in its clouds. Now, we are finally returning to this enigmatic planet after more than thirty
years of absence with four incredible missions that will finally answer the riddle of Venus
and, possibly, life in the wider Universe.
Before we dive into these missions and the implications of their findings, however, we
first need to understand why Venus could harbour life, because, if life exists there, it is
unlike anything we know of on Earth.
The surface of Venus is the epitome of inhospitable. At 900 F⁰ or 475 C⁰, it is the hottest
planet in our Solar System, not to mention the crushing pressures, powerful winds and
an atmosphere made primarily of carbon dioxide. But, in the midst of its sulphuric acid clouds,
the conditions for life are just right.
The temperature is perfect, all the building blocks for life are available, and there is
plenty of chemical energy. So scientists have long theorised that bacteria-like microbes
may thrive in the Venusian atmosphere.
But how would life get going on such a horrific planet? Well, we do have some evidence suggesting
Venus may have once been a much more pleasant planet with a liquid water ocean and temperate
climate. We even have evidence of ancient and current volcanism.
These two factors combined means that it is plausible that billions of years ago, microbial
life started and evolved around Venetian hydrothermal vents, and then evolved to encompass every
nook of the planet. As the environment changed to its present-day vision of hell, however,
only the cloud inhabiting microbes remained.
But all of this is just theory and conjecture based on some very loose evidence. We haven’t
sent a probe to the surface of Venus in over 30 years and the recent data collected by
passing spacecraft or ground-based telescopes here on Earth is vague.
For example, we recently found evidence of phosphine in the atmosphere, a possible sign
of life, but the signal could have also come from sulphur dioxide.
So there is a planet with a known habitable environment with evidence for biosignatures.
Luckily for us, this enticing mystery has attracted NASA, ESA and MIT scientists, who
are now sending four separate missions to search for life on Venus.
Firstly, we have two NASA missions, VERITAS and DAVINCI+, both planned for the late 2020s.
VERITAS is interested in the surface of the planet. An orbiter will use RADAR and gravitational
measurements to understand the topography and composition of the surface. VERITAS aims
to find evidence for oceans and volcanism, past and present. Enabling us to understand
if Venus was ever a habitable planet.
DAVINCI+ is focused on understanding the atmosphere. It will use a parachute lander and orbiting
imager to probe the composition of the Venusian atmosphere to understand how it evolved and
the unique chemistry going on within it.
This will complement VERITAS in understanding Venus’ deep past. It will also help us understand
if Venus’ clouds are genuinely habitable today by getting a complete detailed picture
of the atmosphere’s composition.
Then we have the European Space Agency mission EnVision which is planned to launch in 2031.
This mission will be similar to both the NASA missions as it also aims to understand the
atmospheric composition and geological features. However, EnVision has a slightly different
array of sensors and these will help piece together the timeline of Venus’ ancient
past. So while VERITAS might find evidence of river beds from long ago, EnVision will
help identify how old these structures are.
Finally, we have the MIT mission Venus Life Finder or VLF, which aims to launch onboard
the new Rocket Lab’s Photon launch system as soon as 2023.
This mission is the equivalent of a smash and grab. There will be an array of different
sensors, landers and even a sample return mission. But, unlike the others, VLF isn’t
about understanding Venus’s past. It is directly aimed at finding proof of living
organisms in the atmosphere. As such, this is a high-risk, high-reward mission.
For example, one of these mini-missions includes a balloon probe that will stay within the
habitable zone of the atmosphere and sample for signs of life. If successful, the data
it collects will be priceless.
What makes VLF even more exciting is that it is privately funded. The advent of cheap
launch vehicles like SpaceX’s Falcon 9 and Rocket Lab’s Photon means that wealthy organisations,
such as universities, can now fund daring space missions. Who knows, if VLF goes well,
we may soon have privately funded missions to Jupiter and Saturn’s icy moons in search
of life.
So, what could these incredible missions find?
VLF is do or die, it either will or won’t find life in the Venusian clouds. If VLF does
find life, it will have some shocking implications. This environment is so vastly different from
Earth that if it can support life, it would imply that life may be far more abundant in
the Universe than we previously thought. But, VLF will likely shed light on the unusual
chemistry we see in the Venusian atmosphere, which could be new and unique biosignatures.
The James Web Space Telescope can then use these to find evidence of similar life on
exoplanets throughout our Galaxy. This is a long shot, but by understanding Venus’
possible biosignature in detail, we really could find conclusive proof of life in the
wider Universe.
The three other missions will then answer how life may have started and evolved on such
a weird world, giving us a near-complete picture, from origin to present.
So, over the next decade, we can expect some truly astonishing science to come from Venus,
and the world’s gaze will finally be pulled off of Mars. We live in a time of awe-inspiring
science. We are poised to find life in our own cosmic backyard, and if we do, we have
the equipment ready to find similar life on distant exoplanets hundreds of light-years
away. The Universe is about to become a whole lot more populated, or we are about to discover
just how lonely we really are.
I hope you enjoyed this video. If you did, then please tap the like button and subscribe.
If you want to continue exploring our magnificent universe, then why not watch this video about
what the surface of Mars sounds like. It's surprisedly bizarre. Thank you so much for
watching, and I hope to see you all next time.