很难断定火星表面或大气中是否存在生命，甚至是否存在生命。为了得出结论，正对该理论的两个方面的证据进行极端详细的分析。对火星陨石ALH84001的分析和研究，被认为是迄今为止对火成岩进行的研究最多和最详细的分析。即使对这块陨石进行了如此程度的分析，我们仍然无法对它是否含有外星生命的痕迹作出明确而简明的结论。尽管对碳酸盐球体和细菌形状物体的探测表明，理论上火星上可能存在生命，但反对外星生命理论的科学家不同意，他们认为这些发现表明陨石上存在生命形式。他们认为，由于这些细菌形状的物体体积较小，它们可以代表陨石中的人工制品。对于海盗号和MER号的任务也有一些批评。虽然观测到少量的大气水蒸气，但由于地表缺乏液态水，这一证据还不确定。但是机遇号探测器有一些非常有趣的发现，包括发现赤铁矿。这种矿化的氧化铁可用于水处理的保存。这一发现，连同在梅里迪亚尼平原上发现的类似涟漪的曲线，可能表明许多年前地球表面曾存在过生命形式。
英国曼彻斯特代写essay:火星生命
It is very difficult to conclude whether or not life does or even did exist on the surface or in the Martian atmosphere. Evidence from both sides of the theory are being analysed in extreme detail in order to come to a conclusion. The analyses and study of the Martian meteorite ALH84001, is considered the most studied and detailed analyses ever to be carried out on an igneous rock. Even with this extent of analyses being carried out on the meteorite, we still cannot come to a clear and concise conclusion to whether or not it contained traces of extra-terrestrial life. Although the detection of carbonate globules and bacterial shaped objects suggests that life theoretically could have existed on the planet of Mars, scientists who oppose the theory of extra-terrestrial life disagree that these discoveries indicate a life-form present in the meteorite. They suggest that because of the small size of these bacterial-shaped objects that they could represent artifacts in the meteorite.There was also some criticism about the Viking and MER missions. Although a small amount of atmospheric water vapour was observed, the lack of liquid water on the surface declares this evidence inconclusive. However there was some very interesting discoveries made by the Rover Opportunity, including the detection of hematite. This mineralised form of iron-oxide can be used for the preservation of aqueous processes. This discovery, along with the discovery of ripple-like curves in the Meridiani plain, could indicate a past life-form having existed on the surface of the planet many years ago.
