Archives For Venus

On Monday, May 9 solar observers in North America will be able to see the silhouette of planet Mercury as it passes between Earth and our Sun. The event, called a transit, is relatively rare — though not so rare as a transit of Venus — and may cause interest in viewing the Sun. WARNING: Looking at the Sun, especially through optical instruments, requires extreme caution! Permanent vision damage can result if proper precautions are not taken! Click here for a good article on safely observing the Sun.

At present we DO NOT plan to open Stephens Observatory for the transit but if plans change, the announcement will be made here — check back later. If conditions are clear, we hope to post images made via telescope at a remote location.

Tiny planet Mercury will appear as a correspondingly tiny black dot against the Sun’s brilliant disk. If any sunspots are present on Sol’s face, compare them with Mercury: the planet will be distinctly round and noticeably darker than sunspots, and from minute to minute it will move — sunspot motion takes days!

Image: Planetary positions on May 9, 2016.

May 9 Transit of Mercury – Note how the orbits of Mercury, Venus, and Earth are “tilted” making line-of-sight alignment a rare occurrence.

Viewed from Earth, transits occur when one of the inner planets crosses the line of sight between our world and the Sun; only Venus and Mercury are ever able to do that. A transit, then, is a bit like a solar eclipse only viewed at a greater distance and blocking only a small amount of the Sun’s light.

Transits would occur more often but for the fact that the orbits of Mercury and Venus are “tipped” so that they do not align along the same plane as Earth’s path. Only when the planets are in the right position where the line of sight passes straight through to the Sun do we see transits and with Mercury, that happens only about 13 times per century. After May 9, the next transits of Mercury will take place in November 2019, November 2032, and November 2049. The most recent transit of Venus took place in June 2012 and will not be seen again until December 2117.

Monday’s transit of Mercury will take place over several hours. For us in Northern Ohio, the transit begins at about 7:12 AM Eastern Daylight Time with the Sun low in the east. Midpoint of Mercury’s passage will be at 10:57 AM, and the transit ends at 2:42 PM.

Cloudy skies? Don’t have proper gear to view the Sun? Fret not! There will be “live” webcasts of the event from various sources during Mercury’s passage. Use your favorite web search engine to find good sources and check for a planned broadcast via NASA TV. NASA will stream a live program on NASA TV and the agency’s Facebook page from 10:30 to 11:30 AM — an informal roundtable during which experts representing planetary, heliophysics and astrophysics will discuss the science behind the Mercury transit. Viewers can ask questions via Facebook and Twitter using #AskNASA.

We hope to post a few links here later.

Illustration: January 2016: Five Planets Visible in the Pre-Dawn Sky

January 2016: Five Planets Visible in the Pre-Dawn Sky

 

Over recent weeks we have watched as several planets have appeared close together in our morning sky — when clear, that is — and even seen them shift their positions as the days passed! Beginning this frigid week and continuing into mid-February, five of Earth’s Solar System siblings will be visible, spanning the southern sky. This is the first time since 2005 that this planetary lineup has occurred. If we get a break in morning cloud cover go out, just before dawn’s early light, and look for the planetary parade. Little Mercury will be the hardest to spot being both dim and close to the horizon. Venus and Jupiter will be easy as they are the brightest of the bunch. Golden Saturn and finally reddish Mars should also be easy to find though Mars isn’t a standout. The gathering will occur again late this summer and in the evening sky. The planets aren’t really very much closer together in space during this time. The chart below illustrates the current relative positions of the planets; it’s our point of view from Earth that makes creates the scene: something like watching racers on a race track, appearing closer and farther apart as they run laps in their concentric lanes.

Illustration: January 2016: Planetary Positions - Area Between Lines of Sight Illustrates Area of Space We See

January 2016: Planetary Positions – Area Between Lines of Sight Illustrates Area of Space We See

Image: Jupiter and Venus Converge June 30 - Chart Courtesy Sky & Telescope

Jupiter and Venus Converge June 30 – Chart Courtesy Sky & Telescope

Let’s hope for clear skies the evening of June 30 when the ongoing conjunction of Jupiter and Venus gets really cozy! Tuesday evening will see the two planets sharing a space only 1/3-degree apart in our sky; they will look like a brilliant double star. After Tuesday’s encounter, the planets will drift slowly apart night-by-night but will remain a beautiful sight in twilight. Chart courtesy Sky & Telescope – SkyAndTelescope.com