Month: October 2024

Science idea: Asteroids can take humans to other planets. Like an interplanetary bus…

[The idea also has serious problems with it. It might be impractical. But it is an interesting line of thinking. Jan]

Humans are trying to reach Mars, but a trip on board a spacecraft will cost a lot of money and time, besides tackling several other logistical matters, such as how to battle harmful levels of radiation. Researchers from Ukraine have come up with an innovative way to travel to the red planet – hitchhike your way to a planet on an asteroid.

Asteroids zoom past several planets in the universe and the scientists see it as a solution the cosmos already presents to humans who wish to travel between planets. So why not hop on them to reach Mars?

A trip to Mars will have a huge effect on the physical health of astronauts. It is around 225 million km away from Earth and a journey to and fro will take about three years. This means prolonged exposure to radiation and microgravity, leading to loss of muscles and bone density. Returning to Earth’s gravity will likely become impossible and heart issues are also likely to crop up.

AS Kasianchuk and VM Reshetnyk from the National University of Kyiv in Ukraine, authors of the paper, analysed the orbit of more than 35,000 near-Earth asteroids to understand the possibility of making successive approaches to pairs of planets Earth–Venus and Earth-Mars within a time range of 2020 to 2120.

They say asteroids can be used as interplanetary busses which will prove to be a much faster mode of transport between the planets. The researchers estimate the trips might even be completed within as soon as 180 days.

Several asteroids have been shortlisted
They have zeroed in on 120 candidates for Earth-Mars, Earth-Venus, Mars-Earth, Venus-Earth, and even Mars-Venus and Venus-Mars trips.

If the idea works out, it cancels out the need for creating a spacecraft to carry humans to other planers. However, a technological solution would still be needed to protect one against radiation.

The list of asteroids that can potentially help with planet-hopping will only grow since near-Earth objects are regularly discovered. NASA’s NEO Surveyor mission will prove to be of crucial help in this area as it is working to find more than 90 per cent of all NEOs larger than 140 metres in diameter.

Experts believe the right asteroid can prove extremely useful in the cosmic journey. Astronauts can possibly use it as a fuel station and seek shelter under features like caves to shield themselves from radiation.

Source: https://www.wionews.com/trending/humans-can-hitch-a-ride-to-mars-on-board-an-asteroid-ukrainian-scientists-say-771624

Space Science: Does alien life need a planet to survive? Scientists propose intriguing possibility

While such organisms may or may not exist in the universe, the research has important implications for future human endeavors in space.

What if we dropped the "terrestrial" from "extraterrestrial"? Scientists recently explored the intriguing possibility that alien life may not need a planet to support itself.

At first glance, planets seem like the ideal locations to find life. After all, the only known place life is known to exist is Earth’s surface. And Earth is pretty nice. Our planet has a deep gravitational well that keeps everything in place and a thick atmosphere that keeps surface temperatures in the right ranges to maintain liquid water. We have an abundance of elements like carbon and oxygen to form the building blocks of biological organisms. And we have plenty of sunlight beaming at us, providing an essentially limitless source of free energy.

It’s from this basic setup that we organize our searches for life elsewhere in the universe. Sure, there might be exotic environments or crazy chemistries involved, but we still assume that life exists on planets because planets are so naturally suited to life as we know it.

In a recent pre-paper accepted for publication in the journal Astrobiology, researchers challenge this basic assumption by asking if it’s possible to construct an environment that allows life to thrive without a planet.

This idea isn’t as crazy as it sounds. In fact, we already have an example of creatures living in space without a planet: the astronauts aboard the International Space Station. Those astronauts require tremendous amounts of Earth-based resources to be constantly shuttled to them, but humans are incredibly complex creatures.

Perhaps simpler organisms could manage it on their own. At least one known organism, the tiny water-dwelling tardigrades, are able to survive in the vacuum of space.

Any community of organisms in space needs to tackle several challenges. First, it needs to maintain an interior pressure against the vacuum of space. So a space-based colony would need to form a membrane or shell. Thankfully, this isn’t that big of a deal; it’s the same pressure difference as that between the surface of water and a depth of about 30 feet (10 meters). Many organisms, both microscopic and macroscopic, can handle these differences with ease.

The next challenge is to maintain a warm enough temperature for liquid water. Earth achieves this through the atmosphere’s greenhouse effect, which won’t be an option for a smaller biological space colony. The authors point to existing organisms, like the Saharan silver ant (Cataglyphis bombycina), that can regulate their internal temperatures by varying which wavelengths of light they absorb and which they reflect — in essence, creating a greenhouse effect without an atmosphere. So the outer membrane of a free-floating colony of organisms would have to achieve the same selective abilities.

Next, they would have to overcome the loss of lightweight elements. Planets maintain their elements through the sheer force of gravity, but an organic colony would struggle with this. Even optimistically, a colony would lose lightweight elements over the course of tens of thousands of years, so it would have to find ways to replenish itself.

Lastly, the biological colony would have to be positioned within the habitable zone of its star, to access as much sunlight as possible. As for other resources, like carbon or oxygen, the colony would have to start with a steady supply, like an asteroid, and then transition to a closed-loop recycling system among its various components to sustain itself over the long term.

Putting this all together, the researchers paint the portrait of an organism, or colony of organisms, floating freely in space. This structure could be up to 330 feet (100m) across, and it would be contained by a thin, hard, transparent shell. This shell would stabilize its interior water to the right pressure and temperature and allow it to maintain a greenhouse effect.

While such organisms may or may not exist in the universe, the research has important implications for future human endeavors in space. Whereas we currently construct habitats with metal and supply our stations with air, food and water transported from Earth, future habitats may use bioengineered materials to create self-sustaining ecosystems.

Source: https://www.space.com/does-alien-life-need-a-planet-to-survive?utm_term=AF536F6D-055D-443A-91F7-FD448D0CCA73&lrh=4cd1bd23c622eeb1274411ac3b55b43215b8c098a20f14a3285c9e8ae13a98ca&utm_campaign=58E4DE65-C57F-4CD3-9A5A-609994E2C5A9&utm_medium=email&utm_content=726E1118-D33C-4DAA-BF43-F65E48F8824B&utm_source=SmartBrief