News From the Search for Extraterrestrial Life 7Venus is back in the news, for what it can teach us about what can go wrong with Earth
The search continues. Last week we learned about an ancient ocean on Mars and also that Saturn’s moon Enceladus may be a better bet than Mars for life (in the oceans beneath its icy surface). Meanwhile,
NASA slams the DART into asteroid Dimorphos
NASA successfully struck asteroid Dimorphos, and witnessed the dramatic impact in real time from Earth. Engineers from Johns Hopkins University Applied Physics Laboratory (JHUAPL) in Maryland monitored their DART probe, short for Double Asteroid Rendezvous Test, as it approached the small asteroid on Monday (Sept. 26). This is NASA’s first planetary defense test, which might inform future efforts to change the direction of a dangerous asteroid traveling towards our planet.Doris Elin Urrutia, “The Top Space Stories of the Week” at Space.com ((September 26, 2022)
So we beat the dinosaurs… right …
Here’s what happened when NASA hit the asteroid:
If the asteroid had hit Earth:
The impact of such an asteroid would produce a crater over 1 mile (1.6 km) wide and over 1,200 feet (370 m) deep, knocking down buildings tens of miles away from ground zero. The rock would likely explode close to the ground before its remnants hit the planet’s surface and cause extreme heating that would melt the ground and ignite fires in the area closest to the explosion, according to [Gareth] Collins.
“If the asteroid fell into the ocean, it would produce very large tsunami waves,” said Collins, who together with his colleagues created an online tool (opens in new tab)that enables researchers (and members of the public) to explore impacts of asteroids of various sizes. “But if it happened deep in the ocean, the waves would dissipate to quite low-amplitude waves before reaching the coast,” he added.Teresa Pultarova, “NASA’s DART asteroid impact won’t make Dimorphos hit Earth — but here’s what would happen if it did” at Space.com (September 27, 2022)
In other news, Venus has become fashionable again:
A series of new surface and orbital missions slated for launch by NASA, the European Space Agency (ESA), India, and China is creating a level of new excitement about Venus exploration that hasn’t been seen since NASA’s Magellan radar mapper visited the planet in 1990 and ESA’s Venus Express began orbiting the planet in 2006.
There are two major drivers for all this activity. One is that we need to understand our infernal neighbor with extraordinarily high surface temperatures and pressures, if we are to ever understand extrasolar planetary systems like ours. And secondly, a better understanding of the ravages of climate change here on Earth. We need to understand what went wrong on Venus in order to help improve our own long-term atmospheric models.Bruce Dorminey, “In Planetary Science Circles, Venus Is Now All The Rage” at Forbes (September 23, 2022)
Tours to Venus? Well, you read it here.
Also, some think that super-Earths as the best places to look for life:
Based on current projections, about a third of all exoplanets are super-Earths, making them the most common type of exoplanet in the Milky Way. The nearest is only six light-years away from Earth. You might even say that our solar system is unusual since it does not have a planet with a mass between that of Earth and Neptune.
Another reason super-Earths are ideal targets in the search for life is that they’re much easier to detect and study than Earth-sized planets. There are two methods astronomers use to detect exoplanets. One looks for the gravitational effect of a planet on its parent star, and the other looks for the brief dimming of a star’s light as the planet passes in front of it. Both of these detection methods are easier with a bigger planet.Chris Impey, “Super-Earths May Be the Best Places to Look for Alien Life” at The Conversation (September 24, 2022)
Science media now treat it with respect: “Upcoming Missions Could Search for Ancient Alien Technology Within the Solar System” ( Universe Today, September 27, 2022) Okay, aliens or no aliens, the universe is designed for life. Makes sense when you think about it.
Gravitational constant: 1 part in 1034
Electromagnetic force versus force of gravity: 1 part in 1037
Cosmological constant: 1 part in 10120
Mass density of universe: 1 part in 1059
Expansion rate of universe: 1 part in 10^55
Initial entropy: 1 part in 10 (10^123)Casey Luskin, “The Fine-Tuning of the Universe for Life” at Evolution News (November 8, 2017)
May as well keep looking.
You may also wish to read: News from the search for extraterrestrial life 6 China has found evidence for an ancient ocean on Mars and an international research teams reports that the number of dried-up lakes is higher than thought. Saturn’s moon Enceladus, along with Jupiter’s moon Europa, may be a better bet than Mars for life (in the oceans beneath its icy surface).