Interstellar dust

Only about 0.7 percent of the mass of the interstellar space is within the sort of solid grains, but these grains have a profound effect on the physical conditions within the gas. Their main effect is to soak up stellar radiation; for photons unable to ionize hydrogen and for wavelengths outside absorption lines or bands, the dust grains are far more opaque than the gas. The dust absorption increases with photon energy, so long-wavelength radiation (radio and far-infrared) can penetrate dust freely, near-infrared very well , and ultraviolet relatively poorly. Dark, cold molecular clouds, within which all star formation takes place, owe their existence to dust. Besides absorbing starlight, the dust acts to heat the gas under some conditions (by ejecting electrons produced by the photoelectric effect, following the absorption of a stellar photon) and to chill the gas under other conditions (because the dust can radiate energy more efficiently than the gas then generally is colder). the most important chemical effect of dust is to supply the sole site of molecular hydrogen formation on grain surfaces. It also removes some heavy elements (especially iron and silicon) that might act as coolants to the gas. The optical appearance of most nebulae is significantly modified by the obscuring effects of the dust.

Comments

What is cosmic dust?

What is cosmic dust? The Universe may be a very dusty place. cloud consists of small particles of solid material floating around within the space between the celebs . it's not an equivalent because the dust you discover in your house but more like smoke with small particles varying from collections of just a couple of molecules to grains of 0.1 mm in size. Dust is vital because we discover many it around young stars. actually it helps them to make , and it's also the staple from which planets just like the Earth are formed. The diagram below illustrates the cloud cycle. Dust is made in stars and is then blown off during a slow wind or a huge star explosion. The dust is then ‘recycled’ within the clouds of gas between stars and a few of it's consumed when subsequent generation of stars begins to make . Astronomers wont to consider dust as a nuisance because it absorbs the light from objects, keeping them hidden from our optical telescopes making the Universe app

How NASA Will Protect Astronauts From Space Radiation at the Moon

How NASA Will Protect Astronauts From Space Radiation at the Moon August 1972, as NASA scientist Ian Richardson remembers it, was hot. In Surrey, England, where he grew up, the fields were brown and dry, and other people tried to remain indoors — out of the Sun, televisions on. except for several days that month, his TV picture kept ending . “Do not adjust your set,” he recalls the BBC announcing. “Heat isn’t causing the interference. It’s sunspots.” The same sunspots that disrupted the tv signals led to enormous solar flares — powerful bursts of energy from the Sun — Aug. 4-7 that year. Between the Apollo 16 and 17 missions, the solar eruptions were a mishap for lunar explorers. Had they been in orbit or on the Moon’s surface, they might have experienced high levels of radiation sparked by the eruptions. Today, the Apollo-era flares function a reminder of the threat of radiation exposure to technology and astronauts in space. Understanding and predicting solar eruptions is cru

What is space time?

What is space time? The fabric of space-time may be a conceptual model combining the three dimensions of space with the time of your time . consistent with the simplest of current physical theories, space-time explains the weird relativistic effects that arise from traveling near the speed of sunshine also because the motion of massive objects within the universe. Who discovered space-time? The famous physicist Einstein helped develop the thought of space-time as a part of his theory of relativity. before his pioneering work, scientists had two separate theories to elucidate physical phenomena: Isaac Newton's laws of physics described the motion of massive objects, while James Clerk Maxwell's electromagnetic models explained the properties of sunshine , consistent with NASA. But experiments conducted at the top of the 19th century suggested that there was something special about light. Measurements showed that light always traveled at an equivalent speed, regardle

Space wonder

Search This Blog