What is a molecular cloud for kids?
What is a molecular cloud for kids?
A molecular cloud is a kind of cloud in space. It has enough density and size so that molecules can form, usually molecules of hydrogen (H2).
What is a giant molecular cloud called?
molecular cloud, also called dark nebula, interstellar clump or cloud that is opaque because of its internal dust grains. The form of such dark clouds is very irregular: they have no clearly defined outer boundaries and sometimes take on convoluted serpentine shapes because of turbulence.
How are giant gas clouds formed?
The Short Answer: A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form.
What are giant molecular clouds and what role do they play in star formation?
Star Formation. Stars form inside relatively dense concentrations of interstellar gas and dust known as molecular clouds. These regions are extremely cold (temperature about 10 to 20K, just above absolute zero). At these temperatures, gases become molecular meaning that atoms bind together.
What is necessary for molecular clouds to form?
A molecular cloud is an accumulation of interstellar gas and dust. Such a density can only occur if the temperatures are very low, otherwise the thermal pressure of the gas would lead to an expansion of the dark nebula and no new stars would be able to form.
What is the primary constituent of a molecular cloud?
The primary constituent of molecular clouds, H2, is also the main collision partner with other molecular inhabitants of these regions. These collisions lead to the excitation of rotational transitions in a variety of molecules, many of which emit at observable millimeter wavelengths.
What is the primary constituent of molecular clouds?
How do molecular clouds form stars?
Summary: Stars form in cold, dense regions of space called molecular clouds. When the force of gravity pulling in on the cloud is greater than the strength of internal pressure pushing out, the cloud collapses into a protostar.
What roles do these giant clouds play?
Cloud processes and feedbacks play a large role in the energy balance of Earth s climate system. Some clouds efficiently block out solar radiation, cooling Earth, while others efficiently absorb outgoing infrared radiation, warming the climate.
How is a molecular cloud created?
Why are giant molecular clouds important?
Giant molecular clouds Newly formed stars are visible nearby, their images reddened by blue light being preferentially scattered by the pervasive dust. This image spans about two light-years and was taken by the Hubble Space Telescope in 1999.
Why is it important for a molecular cloud to be cold for star formation?
Molecular clouds are rare, but are important parts of the galaxy where molecules form and evolve. In the colder, denser areas, and under the right conditions, stars are formed. Understanding how molecules are released from dust at low temperatures is crucial to explaining how chemicals evolve in such cold clouds.
Is there such a thing as a giant molecular cloud?
To adequately address topics such as stellar and galactic evolution, it is necessary to address the question of giant molecular cloud (GMC) formation and evolution, topics that continue to be actively debated in astrophysics.
What is the angular momentum of molecular cloud gradients?
If the molecular cloud gradients – ranging from 0.04 to 0.20 km s -1 pc -1 – are due to rotation, their angular momentum is always less than that in the surrounding HI.
What happens to the jeans limit when a cloud collapses?
(1) it is obvious that as the density of the cloud is increased with collapse the temperature of the cloud is increased (without some rapid cooling method; i.e. radiated away) and the required Jeans mass increases, as does the required Jeans length [Eq. (2)]. This runs counter to a collapse through the Jeans limit.
What happens to the temperature of a cloud when it collapses?
And it is assumed that the cloud is isothermal. It must be optically thin; meaning transparent to all radiation thus no heat is absorbed by the cloud. Thus the cloud remains at constant temperature during the collapse. More assumptions and more storytelling.
