一項新的研究給火星生命的希望帶來了巨大的打擊

一項新的研究給火星生命的希望帶來了巨大的打擊

Of all the planets in our solar system, Mars is thought to be our best chance at finding life outside of Earth. There’s obviously not much happening on the surface, but pockets of ice and even water exist in some areas of the planet, and there’s a tiny, almost impossibly slim chance that something very tiny might be living there.

在我們太陽系的所有行星中，火星是我們在地球之外尋找生命的最佳機(jī)會。表面上不太可能，但是在這顆星球的某些區(qū)域存在著冰甚至水，所以在那里生存的機(jī)會還是有非常微小的可能的。

Or, at least that’s what some scientists were hoping for, but a new study published by researchers from several institutions suggests that even that narrow possibility is probably also nonexistent.

或者，至少這是一些科學(xué)家所希望的，但來自幾個機(jī)構(gòu)的研究人員發(fā)表的一項新研究表明，即使是這種微小的可能性也可能不存在。

We think we have a pretty good idea of what ingredients are required for life to exist. One of the big ones is water, and Mars has it. Much of it is locked away in ice, but Mars also has salt, and the combination of water and salt dramatically lowers its freezing point, meaning that puddles of ultra-salty brine could still exist on the surface.

我們以為我們對生命存在所需要的成分有了很好的了解。其中最大的一個是水，火星上就有水。火星上的大部分冰都被鎖住了，但火星上也有鹽，水和鹽的結(jié)合大大降低了火星的冰點，這意味著火星表面仍然可能存在超咸鹽水坑。

To determine the likelihood that such puddles could support life, the researchers built an atmospheric model based on what we already know about the planet. Then using the simulated climate, they tested whether briny puddles could persist for long periods of time. Unfortunately, the data points in the opposite direction of life.

為了確定這些水坑能夠維持生命的可能性，研究人員根據(jù)我們對火星的了解建立了一個大氣模型。然后利用模擬的氣候，他們測試了鹽水水坑是否能長期存在。不幸的是，這些數(shù)據(jù)指向相反的方向。

“Our team looked at specific regions on Mars — areas where liquid water temperature and accessibility limits could possibly allow known terrestrial organisms to replicate — to understand if they could be habitable,” Dr. Alejandro Soto, co-author of the study, said in a statement. “We used Martian climate information from both atmospheric models and spacecraft measurements. We developed a model to predict where, when and for how long brines are stable on the surface and shallow subsurface of Mars.”

我們的團(tuán)隊研究了火星上的特定區(qū)域——液態(tài)水溫度和可接近性限制可能允許已知陸地生物復(fù)制的區(qū)域——以了解它們是否適合居住，”該研究的合著者亞歷杭德羅·索托博士在一份聲明中說。“我們使用了來自大氣模型和航天器測量的火星氣候信息。我們開發(fā)了一個模型來預(yù)測鹽水在火星表面和淺地下穩(wěn)定的時間、地點和持續(xù)時間。”

The results showed that even under the most favorable conditions, puddles of super-salty water would only be stable on the planet’s surface during certain times of the year.

結(jié)果表明，即使在最有利的條件下，超咸水坑也只會在一年中的某些時候穩(wěn)定地存在于火星表面。

“Even extreme life on Earth has its limits, and we found that brine formation from some salts can lead to liquid water over 40% of the Martian surface but only seasonally, during 2% of the Martian year,” Soto says. “This would preclude life as we know it.”

索托說：“即使是地球上最極端的生命也有其局限性，我們發(fā)現(xiàn)，一些鹽類形成的鹽水可以形成火星表面40%以上的液態(tài)水，但這是有季節(jié)性的，只占火星一年內(nèi)2%的時間。”。“所以，我們所知的生命是無法在這里生存的。”

So yeah, that’s a bit of a bummer. The good news is that NASA’s Perseverance rover will soon be headed to Mars, and it’ll be gathering samples of the surface and conducting experiments that could reveal whether life has ever existed on the planet.

所以，是的，有點令人沮喪。好消息是，美國宇航局的“Perseverance”號探測器不久將前往火星，它將收集火星表面的樣本，并進(jìn)行實驗，以確定火星上是否曾存在生命。