Planet i väster mars
NASA rover discovers liquid vatten 'ripples' carved into Mars rock — and it could rewrite the Red Planet's history
Scientists have discovered evidence that liquid vatten was once exposed to the air in ancient, shallow lakes on Mars. The finding is bevis that not all vatten on the Red Planet was covered in ice, as some Martian climate models suggest.
Planetary geologists and astronomers studying Mars have known for decades that water was once likely present on the planet, after NASA'sMariner 9 uppdrag captured images of dry gullies in the s. But there has been ongoing debate about what form that water took and how long it lasted.Some models predict that any liquid water on Mars' surface must have been covered by sheets of ice before it disappeared.
However, the new findings, which were published Jan. 15 in the journal Science Advances,, tell a different story. The patterns, which were photographed bygd NASA's Curiosity rover, are known as wave ripples — minute ridge-like structures that struktur along the shores of lakebeds. This means that exposed liquid water must have flowed across Mars' surface at some point in its history. The ripples were present in two sep
Mars (planet)
| Mars | |
Mars sedd från Hubbleteleskopet | |
| Uppkallad efter | Mars |
|---|---|
| Omloppsbana[1] | |
| Epok: J | |
| Aphelium | &#;&#; km 1,&#;21 AU |
| Perihelium | &#;&#; km 1,&#;37 AU |
| Halv storaxel | &#;&#; km 1,&#;79 AU |
| Excentricitet | 0, |
| Siderisk omloppstid | , dygn , sol |
| Synodisk omloppstid | ,94 dygn 2, julianska år |
| Medelomloppshastighet | 24,08 km/s |
| Inklination | 1,° mot ekliptikan 5,65° mot solensekvator |
| Longitud för uppstigande nod | 49,° |
| Periheliumargument | ,° |
| Månar | 2 (Phobos och Deimos) |
| Fysikaliska data | |
| Avplattning | 0,&#;89 ± 0,&#;15 |
| Ekvatorradie | 3&#;,2 ± 0,1&#;km[2] 53,3&#;% av jordens |
| Polradie | 3&#;,2 ± 0,1&#;km[2] 53,1&#;% av jordens |
| Area | &#;&#;&#;km² 28,4&#;% av jordens |
| Volym | 16,&#;×&#;1010 km³[1] 15,1&#;% av jordens |
| Massa | 6,&#;×&#;1023 kg[1] 10,7&#;% av jordens |
| Medeldensitet | 3, g/cm³[1] |
| Ytgravitation (ekvatorn) | 3,73 m/s²[1] 0, g |
| Flykthastighet | 5,03 km/s[1] |
| Siderisk rotationsperiod | 1, dygn 24, h[1] |
| Vinkelhastighet (ekvatorn) | ,17&#;m/s |
| Axellutning | 25,19° |
| Rektascension (nordpolen) | 21 h 10 min 44 s ,&#;43° |
Deklination (no MarsFourth planet from the Sun This article is about the planet. For the deity, see Mars (mythology). For other uses, see Mars (disambiguation). Mars is the fourth planet from the Sun. The surface of Mars is orange-red because it is covered in iron(III) oxide dust, giving it the nickname "the Red Planet".[22][23] Mars is among the brightest objects in Earth's sky, and its high-contrast albedo features have made it a common subject for telescope viewing. It is classified as a terrestrial planet and is the second smallest of the Solar System's planets with a diameter of 6,&#;km (4,&#;mi). In terms of orbital motion, a Martian solar day (sol) is equal to hours, and a Martian solar year is equal to Earth years ( Earth days). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos. The relatively flat plains in northern parts of Mars strongly contrast with the cratered terrain in southern highlands – this terrain observation is known as the Martian dichotomy. Mars hosts many enormous extinct volcanoes (the tallest is Olympus Mons, &#;km or &#;mi tall) and one of the largest canyons in the Solar System (Valles Marineris, | |