How do we know the age of the surfaces we see on planets and moons? If a world has a surface as opposed to being mostly gas and liquid , astronomers have developed some techniques for estimating how long ago that surface solidified. Note that the age of these surfaces is not necessarily the age of the planet as a whole. On geologically active objects including Earth , vast outpourings of molten rock or the erosive effects of water and ice, which we call planet weathering, have erased evidence of earlier epochs and present us with only a relatively young surface for investigation. One way to estimate the age of a surface is by counting the number of impact craters. This technique works because the rate at which impacts have occurred in the solar system has been roughly constant for several billion years. Thus, in the absence of forces to eliminate craters, the number of craters is simply proportional to the length of time the surface has been exposed.
HS-ESS1-6 Earth’s Place in the Universe
Sources and movement of heat within planets Primordial heat. The general term for the heat imparted to a planetary body by the processes of its formation and differentiation. It is concentrated at the surface.
This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the.
It attracted funding from the U. Army just prior to U. It remains a unit of the California Institute of Technology. In the decades since its founding, the laboratory, first under U. Army direction and then as a NASA field center, has grown and evolved into an internationally recognized institution generally seen as a leader in solar system exploration but whose portfolio includes substantial Earth remote sensing. After developing short-range ballistic missiles for the Army, the laboratory embarked on a new career in lunar and planetary exploration through the early s and abandoned its original purpose as a propulsion technology laboratory.
Lunar & Planetary Surface Power Management & Distribution (SBIR)
Terrestrial planets have hard surfaces that can be re-shaped by several different processes: impact cratering, volcanism, erosion, and tectonics. Impact Cratering There are still small chunks of rock orbiting the Sun left over from the formation of the solar system. Some of them have orbits that cross the orbits of the planets and moons. When they get close enough to a planet or moon, they will be pulled in by the large body’s gravity and strike the surface at a speed of at least the escape velocity of the planet or moon, i.
At such speeds, the projectile explodes on impact and carves out a round bowl-shaped depression on the surface.
Thus, we can use the methods of radiometric dating to determine the age of a Solar radiation is a significant contributor of heat to the planets’ surfaces and.
For this reason, you should use the agency link listed below which will take you directly to the appropriate agency server where you can read the official version of this solicitation and download the appropriate forms and rules. Lead Center: GRC. Technology Area: 3. Related Subtopic Pointer s : Z1. Scope Title. Scope Description. A major factor in this involves establishing bases on the lunar surface and eventually Mars.
At a minimum, crater-age dating can tell you the relative ages of surfaces (which surface is older than another). Careful studies of how the craters.
Over the last couple of days I have fallen down a research rabbit hole — I began with a question about clay minerals on Mars and find myself, today, writing about the history of major impact basins on the Moon. The trail that led me here has to do with geologic time scales — the stories that geologists tell about the major events that happened in the history of a planet. I will climb back out of the rabbit hole eventually with lots of good stories about the geology of many different planets, but I’m going to have to tell those stories bit by bit.
It all begins, appropriately, with the history of impact basins on the Moon. I think that’s appropriate because the Moon is where the study of planetary geology started, even before the Space Age. The familiar face of the Moon contains dark splotches, the maria. Look at the maria with a telescope, and you can see that they’re flat plains that appear to fill low-lying areas. And most of those low-lying areas are circular basins rimmed by mountainous ridges.
We know now that these are impact basins, places where asteroids slammed into the Moon. Arguably the most beautiful of the Moon’s basins is Orientale, whose glory we really couldn’t appreciate until the Space Age, because its eastern edge just peeks over the visible near side of the Moon. Here is a lovely view from Lunar Reconnaissance Orbiter.
FAQ – Radioactive Age-Dating
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A computer-simulated image of the planet Venus, using images of the surface It provided some of the only photographs of the Venusian surface to date.
We’re open! Book your free ticket in advance. The colouration was based on images recorded by the Venera 13 and 14 spacecraft. Venus is the hottest planet in our solar system. This hostile world is covered in thousands of volcanoes and is encased in a dense layer of toxic clouds, swept along by constant hurricane-force winds. Owing to similarity in size, mass and composition, Venus is sometimes called Earth’s sister planet. With an equatorial circumference of 38, kilometres and radius of 6, kilometres, Venus is only marginally smaller than Earth.
Venus has an iron core around the same size as Earth’s – approximately 3, kilometres in radius. But due to a weak magnetic field, which in part relies on convection in the core, it has been suggested that Venus’s core may be predominantly solid. A colourised image of Venus taken by the Galileo Orbiter in from a distance of approximately 1. It was taken through a violet filter and colourised to a bluish hue, emphasising the subtle differences in the thick clouds.
Earth Sciences 4001Y: Planetary Surfaces Field School
GSA Bulletin ; 88 8 : — The need to determine relative ages of materials and surfaces on moons and planets other than the Earth has resulted in the development of dating techniques that are based on the density or the morphology of craters and that supplement the classical techniques of physical stratigraphy. As is the case with the fossil-based relative time scale on Earth, crater-based relative ages can, in principal, be calibrated with radiometric ages of returned samples.
Relative ages determined by crater density or crater morphology rest on a small number of basic assumptions concerning the morphology of fresh craters, the randomness of crater-formation processes, and the rates and areal constancy of crater-degradation processes. The validity of these assumptions varies from planet to planet. Despite the problems and controversies that inevitably accompany the development of major new techniques, the basic principles underlying the use of craters to determine relative ages are well established and logically sound.
Heavily cratered surfaces on the Moon, Mars, and Mercury show that Those isotopic dating studies were state-of-the-art at the time, but the Ar.
How do we know the age of Earth and other planetary bodies? A new study reveals our current techniques are bang-on. By Lewis Dartnell. W hen planetary scientists are trying to understand the surfaces of planets and other worlds in our Solar System, and the processes that form and shape them, the ages of different features is a crucial detail. What would be so much more useful to know is the absolute age of particular surfaces — for example, this volcanic plain is million years old, but that one erupted only 60 million years ago.
On Earth, one of the main methods we use to date the formation of geological strata is to measure the amounts of different radioactive isotopes the rock contains. Unfortunately, when it comes to our exploration of other planets, this sort of measurement is currently impossible for the instruments aboard lander probes such as the Curiosity rover on Mars. Luckily, planetary scientists do have a trick up their sleeve. In general, the older a planetary surface is, the more impacts to which it will have been exposed.
Craters accumulate over time like raindrops on a paving slab during a light drizzle, and so finding relative ages becomes a process of crater-counting. But in order to calculate a much more useful estimate of the absolute age of a surface, you also need to know the rate that impacts of different sizes occur through the Solar System.
And this is why the Apollo Moon missions were so valuable. The Apollo crews collected rock samples from known locations on the lunar surface and brought them back to labs on Earth so that the radioactive isotopes could be measured for more on this, read our article on what the Apollo lunar samples have taught us about the Moon.