One of the more persuasive arguments in favor of the potential existence of life beyond Earth is that the well-known chemical building blocks of that life are found throughout the galaxy. These chemical components aren't all present in all examined solar systems and planets, but they are common and behave in ways familiar to scientists …
Continue reading "Many Planets Form in a Soup of Life-Friendly Organic Compounds"
Red dwarf suns are the most common in the universe, and many of the exoplanets officially discovered so far orbit this type of "cool" star. Red dwarfs are much smaller and less powerful than the G type stars such as our own sun, and it is easier to detect exoplanets orbiting them because of their …
Astronomers have many theories about how planets are formed within the gas, dust, pebbles and gradually rocks of the circumstellar disks that encircle a star after it has been born. While the general outlines of this remarkable process are pretty well established, many questions large and small remain unanswered. One is how and when exomoons …
Continue reading "A Young Planet Found That May Well Be Making Moons"
Artist illustration of the EnVision orbiter at Venus (ESA/VR2Planets/DamiaBouic) It was quite a week for Venus scientists. Just seven days after NASA announced the selection of two Venus missions, DAVINCI+ and VERITAS, the European Space Agency (ESA) revealed that a third Venus mission had been chosen for the agency’s medium-class mission category. (See last week’s …
Continue reading "And Then There Were Three: ESA Follows NASA in Selecting a Mission to Venus"
Artists’ renderings show the VERITAS spacecraft (left) and DAVINCI+ probe (right) as they arrive at Venus (Lockheed Martin). For NASA scientists, Venus missions must feel like buses. You wait thirty years for one, and then two come along at once. Last week, NASA selected two Venus missions for the space agency’s Discovery Program; solar system …
When our sun was young, it was significantly less luminous and sent out significantly less warming energy than it does now. Scientists estimate that 4 million years ago, when the sun and our solar system were 500 million years old, the energy that the sun produced and dispersed was about 75 percent of what it …
Deep inside the rocky planets of our solar system, as well as some solar system moons, is an iron-based core. Some, such as Earth's core, have an inner solid phase and outer molten phase, but the solar system cores studied so far are of significantly varied sizes and contain a pretty wide variety of elements …
Our solar system has but one planet orbiting in what is commonly known as the habitable zone -- at a distance from the host star where water could be liquid at times rather than always ice or gas. That planet, of course, is Earth. But from a theoretical, dynamical perspective, does this always have to …
Continue reading "How Many Habitable Zone Planets Can Orbit a Host Star?"
For space scientists of all stripes, few goals are as crucial as bringing pieces of Mars, of asteroids, of other planets and moons back to Earth for the kind of intensive study only possible here. Space missions can, and have, told us many truths about the solar system, but having a piece of Mars …
From the perspective of planet hunters and planet characterizers, a desirable solar system to explore is one that is close to ours, that has a planet (or planets) in the star's habitable zone, and has a host star that is relatively quiet. This is especially important with the very common red dwarf stars, which are …
Continue reading "Close and Tranquil Solar System Has Astronomers Excited"
Many Worlds 