Related Experiment Video
Updated: Jul 12, 2026

11:10
Conducting Miller-Urey Experiments
Published on: January 21, 2014
Planetary science. Nitrogen on the moon
1Physics Department, University of Minnesota, Minneapolis 55455, USA. rhbecker@tc.umn.edu
Abstract:
The nitrogen isotopic compositions seen in lunar soils have long been a mystery to planetary scientists. As Becker discusses in his Perspective, new techniques, such as the depth profiling of mineral grains reported by Hashizume et al., are now shedding some light on the matter, allowing some theories to be excluded. Nevertheless, the relative role of the solar wind and other processes remains hotly debated.
Related Concept Videos
States of Water
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
What is Weather?
Overview
What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
Escape Velocities of Gases
To escape the Earth's gravity, an object near the top of the atmosphere at an altitude of 100 km must travel away from Earth at 11.1 km/s. This speed is called the escape velocity. The temperature at which gas molecules attain the rms speed, which is equal to the escape velocity, can be estimated by using the equation for the average kinetic energy of the gas molecules. According to the kinetic theory of gas, the average kinetic energy of the gas molecules is proportional to its temperature.
Gas Solubility
Gas solubility in liquids forms liquid-gas solutions, such as soft drinks, where carbon dioxide is dissolved in water, and the ocean, where the solubility of oxygen and carbon dioxide supports marine life. The ability of oceans to dissolve gases impacts weather conditions in the troposphere.However, gas-liquid interactions vary. For instance, hydrogen chloride gas is highly soluble in water, while oxygen's solubility is much lower. Because these solutions are non-ideal, Raoult’s law, which...
Microbes and the Carbon Cycle
The carbon cycle is a fundamental Earth process involving the transfer of carbon among the biosphere, lithosphere, atmosphere, and hydrosphere. It plays a critical role in regulating the planet’s climate and supporting life by cycling carbon through various chemical forms and reservoirs. Carbon primarily circulates as carbon dioxide (CO₂), representing its oxidized form, while reduced forms such as methane (CH₄) and organic compounds also play essential roles.Microbial activity is central to...

