For most of us dust is something dirty that has to be cleaned up, But the tiny particles that float about and settle on surfaces play an important role in a variety of processes on Earth and across the solar system. So put away that feather duster for a few moments as I share some surprising facts about this dust. (Like, share and subscribe to the email list to get notifications about my latest posts)
(Check out my post on interstellar dust to know more: https://www.pratha.info/post/interstellar-dust)
(note: for any question you can use the comment section or the forum. I'll be happy to answer them)
1. It is everywhere!
Just like light, dust is everywhere- It occupies the empty spaces in the universe, it is present around us, some of it may even be on us!
2. Dust is what set the solar system going!
We all have heard about the giant swirling rotating cloud that burst and created the planets and the sun and other components of our solar system. Well, it was a dust cloud.
3. Cosmic dust is really very tiny.
The particles can me as tiny as 1/1000th if a millimeter. They are mostly made up of carbon, soot-like particles, silicon etc. It is common to find small grains of ice as well
4. From a certain point of view.
Dust is easier to see from a certain angle as the light scattered from the dust particles varies depending on the size of the particle. Because of this, structures like planetary rings made of the finest dusty particles are best viewed with the sun illuminating them from behind. For example, Jupiter’s rings were only discovered after the Voyager 1 spacecraft passed by the planet, where it could look back and see them backlit by the sun.
5. Antarctica is dusty!
Cosmic dust is easier to find in some places than the others and one of the bets place on Earth is Antarctica. We find abundant amounts of cosmic dust in Antarctica the reason being that there is not water there. Yes ice and snow are a form of water but to alter dust we need liquid water. Cosmic dust survives for millions of years over here.
Rings on giant planets contain dust. Jupiter’s rings are made of fine rock dust. Saturn’s rings are mostly pure water ice, with a sprinkling of other materials. (Side note about Saturn’s rings: While most of the particles are boulder-sized, there’s also lots of fine dust, and some of the fainter rings are mostly dust with few or no large particles.) Dust in the rings of Uranus and Neptune is made of dark, sooty material, probably rich in carbon.
7. Moon dust is magical but it can make you sick as well.
When the Apollo astronauts visited the Moon, they found that lunar dust quickly coated their spacesuits and was difficult to remove. It was quite abrasive, causing wear on their spacesuit fabrics, seals and faceplates. It also clogged mechanisms like the joints in spacesuit limbs, and interfered with fasteners like zippers and Velcro. The astronauts also noted that it had a distinctive, pungent odor, not unlike gunpowder, and it was an eye and lung irritant.
8. Dust is what makes comets so pretty.
Most comets are basically clods of dust, rock and ice. Some of the dust also is drawn out in long trail – the comet’s tail.
9. A detective will be pleased.
Cosmic dust particles can be millions of years old and so they help to solve some to the big mysteries of the universe. For example, how did our solar system form? Is our solar system typical of other planetary systems. Galaxies, including our Milky Way, contain giant clouds of fine dust that are light-years across – the ingredients for future generations of planetary systems like ours.
10. Dust storms are common on Mars
Local dust storms occur frequently on Mars, and occasionally grow or merge to form regional systems, particularly during the southern spring and summer, when Mars is closest to the sun. A few of these events may become truly global storms, such as one in 1971 that greeted the first spacecraft to orbit Mars, NASA’s Mariner 9. In mid-2018, a global dust storm enshrouded Mars, hiding much of the red planet’s surface from view and threatening the continued operation of NASA’s uber-long-lived Opportunity rover. We’ve also seen global dust storms in 1977, 1982, 1994, 2001 and 2007.
11. Detection of dust.
At the Earth, generally, an average of 40 tons per day of extraterrestrial material falls to the Earth. The Earth-falling dust particles are collected in the Earth's atmosphere using plate collectors under the wings of stratospheric-flying NASAairplanes and collected from surface deposits on the large Earth ice-masses (Antarctica and Greenland / the Arctic) and in deep-sea sediments.
Don Brownlee at the University of Washington in Seattle first reliably identified the extraterrestrial nature of collected dust particles in the later 1970s.
In interplanetary space, dust detectors on planetary spacecraft have been built and flown, some are presently flying, and more are presently being built to fly.
Cosmic dust can be detected by indirect methods utilizing the radiative properties of cosmic dust. Cosmic dust can also be detected directly using a variety of collection methods and from a variety of collection locations.