The Hubble Space Telescope recently captured a photo sequence of four moons of Saturn passing in front of their parent planet. The moons, from far left to far right, are icy white Enceladus and Dione, the large orange moon Titan, and icy Mimas. Due to the angle of the Sun, they are each preceded by their own shadow.
These rare moon transits only happen when the tilt of Saturn's ring plane is nearly "edge on" as seen from the Earth. Saturn's rings will be perfectly edge on to our line of sight on 10 August and 4 September 2009. Unfortunately, Saturn will be too close to the Sun to be seen by viewers on Earth at that time. This "ring plane crossing" occurs every 14-15 years. In 1995-96 Hubble witnessed the previous ring plane crossing, as well as many moon transits, and helped to discover several new moons of Saturn.
Early 2009 was a favorable time for viewers with small telescopes to watch moon and shadow transits crossing the face of Saturn. Titan, Saturn's largest moon, crossed Saturn on four separate occasions: 24 January, 9 February, 24 February and 12 March, although not all events were visible from all locations on Earth.
Cropped look at Enceladus, Dione, Titan, Mimas. CLICK IMAGE FOR FULL SIZE. Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)
Italian Galileo Galilei — often referred to as the father of astronomy — was the first to observe Saturn through a telescope in 1610. Dutch mathematician and astronomer Christian Huygens discovered Titan in 1655 and, 350 years later, the ESA probe named for him touched down on Titan (on 14 January 2005), giving the world its first views of the surface of the mysterious, icy world. Giovanni Domenico Cassini, a French/Italian astronomer, discovered Dione (in addition to others) and the German-born Englishman, William Herschel, discovered Mimas and Enceladus.
These pictures were taken with Hubble's Wide Field Planetary Camera 2 on 24 February 2009, when Saturn was at a distance of roughly 1.25 billion kilometres from Earth. Hubble can see details as small as 300 kilometres across on Saturn. The dark band running across the face of the planet slightly above the rings is the shadow of the rings cast on the planet.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Swarm Bots Kill Mass Shooter
- Can A New Rule Trigger A Second EU Referendum? Petition 4 Millon Signatures, Nearly 12% Of Total Votes Cast
- Nanotech: The Most Dangerous Science Least Carefully Done
- How A Former Naturopath Can Help Unravel The Trickery of Alternative Medicine
- A Billion Years Ago, What Did Earth's Ancient Magnetic Field Look Like?
- Understanding Rogue Ocean Waves May Be Simple After All
- How A Woman With Amnesia Defies Conventional Wisdom About Memory
- "Hi Anlain, it explains on the page itself. It's a post vote survey - not a poll, so more accurate..."
- "If british elections and referenda are supposed to be secret ballots,how can statistics like those..."
- "If you really wanted to know the truth you could find many researched and peer reviewed articles..."
- "So how many people with HIV, HCV, Parkinson's, MS, Hansen's disease, etc etc etc are being cured..."
- "Hi Robert; Hope you are doing well. Just wanted you to know that I've put up a new video regarding..."
- Summer Camp Means Fun for Kids, But Panic for Some Parents
- Swayed By Lunch Money: A Grotesque Insult to Doctors
- Sensing Too Much Zika Exposure, Golfers Continue Olympic Exodus
- Cannabis Beverages: A New Way to Get High
- Got Zika? Thank an Environmentalist
- Magical Moron Moments: Burn Your Feet with Tony Robbins
- Lung cancer experts seek public comments on revised molecular testing guideline
- Lab-tested diagnosis needed when treating patients with persistent diarrhea
- No need in supercomputers
- 'Squishy' motors and wheels give soft robots a new ride
- High expectations of CERN -- focus on particle physics at Lindau Nobel Laureate Meeting