Artikel: is asteroide in de ruimte een ruimteschip van aliens?

Matt Williams / Phys.org

On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar asteroid, named 1I/2017 U1 (aka, “Oumuamua). In the months that followed, multiple follow-up observations were conducted that allowed astronomers to get a better idea of its size and shape, while also revealing that it had the characteristics of both a comet and an asteroid.

Interestingly enough, there has also been some speculation that based on its shape, ‘Oumuamua might actually be an interstellar spacecraft (Breakthrough Listen even monitored it for signs of radio signals!). A new study by a pair of astronomers from the Harvard Smithsonian Center for Astrophysics (CfA) has taken it a step further, suggesting that ‘Oumuamua may actually be a light sail of extra-terrestrial origin.

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Artikel: Dichtstbijzijnde exoplaneet zou zeer leefbaar kunnen zijn

Adam Mann / Livescience

Just a cosmic hop, skip and jump away, an Earth-size planet orbits the closest star to our sun, Proxima Centauri.

Ever since the discovery of the exoplanet — known as Proxima Centauri b— in 2016, people have wondered whether it could be capable of sustaining life.

Now, using computer models similar to those used to study climate change on Earth, researchers have found that, under a wide range of conditions, Proxima Centauri b can sustain enormous areas of liquid water on its surface, potentially raising its prospects for harboring living organisms. [9 Strange, Scientific Excuses for Why Humans Haven’t Found Aliens Yet]

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Artikel: Nearby alien planet may support life

Mike Wall / Space.com

One of the nearest exoplanets to Earth may be a decent abode for life.

Ross 128b — which lies just 11 light-years from our planet — is likely a rocky and temperate world, a new study suggests.

“Although Ross 128b is not Earth’s twin, and there is still much we don’t know about its potential geologic activity, we were able to strengthen the argument that it’s a temperate planet that could potentially have liquid water on its surface,” lead author Diogo Souto, of the Observatório Nacional in Rio de Janeiro, Brazil, said in a statement. [10 Exoplanets That Could Host Alien Life]

Ross 128b has excited and intrigued astrobiologists since its discovery last year. The planet appears to circle in the “habitable zone” of its host star — that just-right range of distances where liquid water could exist on a world’s surface. (Ross 128b circles a small, dim red dwarf star, so the habitable zone is quite close in; the planet completes one orbit every 9.9 Earth days.)

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Artikel: Alien life may be rare in our galaxy today

Nola Taylor Redd / Space.com

The hunt for E.T. may have gotten more difficult. New research suggests that alien life may not be as widespread as we had hoped.

When it comes to hunting for alien civilizations, a key question is how plentiful intelligent extraterrestrials are in the universe — but the answer to that question depends on a lot of knowledge scientists don’t have yet.

In 1960, Frank Drake, an astronomer and hunter of extraterrestrial intelligence, devised an equation to calculate the probability of hearing from an intelligent, communicating alien civilization. The Drake equation relies on the values of several constants to determine how widespread such civilizations might be, how likely they are to evolve and how likely they are to have broadcast when we were able to detect. While some of the numbers, such as how many stars have planets around them, are fairly well-known, others, such as the fraction of those worlds with life, remain uncertain. [The Father of SETI: Q&A with Astronomer Frank Drake]

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Artikel: Is leven in het Alpha Centauri stelsel mogelijk?

Mike Wall / Space.com

The levels of X-ray radiation streaming from Alpha Centauri A and B — two of the three stars in the nearest solar system to our own — are comparable to those emitted by our own sun, according to a new study based on observations by NASA’s Chandra X-ray Observatory.

“This is very good news for Alpha Cen AB in terms of the ability of possible life on any of their planets to survive radiation bouts from the stars,” study lead author Tom Ayres, of the University of Colorado Boulder, said in a statement. “Chandra shows us that life should have a fighting chance on planets around either of these stars.” [Mission to Alpha Centauri: Breakthrough Starshot in Pictures]

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Artikel: Op Mars wemelt het van de aanwijzingen voor leven

Maarten Keulemans / De Volkskrant

Of nou ja: leven, waarschijnlijk in de vorm van microscopisch kleine microbes, is op de rode planeet niet aangetoond. Nóg niet, want nieuwe, vrijdag gepubliceerde metingen van het Marswagentje Curiosity maken de boel er wel spannender op.

Voor het eerst weet Curiosity hard te maken dat er in de bodem afbraakproducten liggen van ingewikkelde organische verbindingen, de bouwstenen van leven. Bovendien bevestigen de metingen definitief wat veel astronomen al aannamen: dat er ’s zomers vanuit het binnenste van de rode planeet methaangas (CH4) ontsnapt. ‘Nu we dit gedetecteerd hebben, kunnen allerlei alternatieve scenario’s die men had uitgedacht van tafel’, zegt astrobioloog Inge Loes ten Kate (Universiteit Utrecht), die de nieuwe waarnemingen in Science voorziet van duidend commentaar.

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