What you need to know for Monday’s rare Mercury transit, including the cloud forecast
By
Brian Lada, AccuWeather meteorologist
Published Nov 5, 2019 5:39 PM EDT
Grab your telescopes and get some solar filters ready. A rare transit of Mercury across the sun will occur on Nov. 11. This rare astronomical event won't happen again until 2032, so don't miss out!
One of the biggest astronomy events of the year will take place at the start of this week. It's an event so rare that it won’t happen again until 2032.
On Monday, Nov. 11, people across North America, South America, Europe, Africa and western Asia will be able to see Mercury pass directly between the Earth and the sun in an astronomical alignment known as a transit.
Transits happen only a few times per century and provide a unique opportunity to see a planet glide across the face of the sun.
People will have a few hours to observe the event, which starts at 7:35 a.m. EST and lasts until 1:04 p.m. EST.
The planet Mercury is seen in silhouette, lower left of image, as it transits across the face of the sun, Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)
Similar to a total solar eclipse, spectators will need a solar filter to shield their eyes from the harmful rays from the sun. Looking at the sun without a solar filter can lead to permanent eye damage and, in some cases, blindness.
However, onlookers will need more than just a solar filter to see the Mercury transit.
“Because Mercury is so small from our perspective on Earth, you'll need binoculars or a telescope with a Sun filter to see it,” NASA said.
It is imperative to have a certified solar filter on the part of the telescope where light enters. Wearing solar filters, such as solar eclipse glasses, and looking into the eyepiece of a telescope that is not outfitted with a filter of its own can still lead to irreversible eye damage.
The American Astronomical Society (AAS) says that the filters should comply with the ISO 12312-2 international safety standard. This number should appear with the filter’s original packaging or on the filter itself.
“Filters that are ISO 12312-2 compliant not only reduce visible sunlight to safe and comfortable levels but also block solar UV and IR radiation,” the AAS explained on their website.
NASA is showing people what happens if you look through a telescope or binoculars that does not have the proper solar filter. “Thanks to Vince Patton for this demonstration of what happens if you combine eclipse glasses and binoculars. Remember melting things in the sun with magnifying glasses? Don't let that be your eye!” (NASA/Vince Patton)
People will need not only the right equipment to see the Mercury transit but also cloud-free weather.
The best viewing conditions will be across the north central and southwestern United States where clear skies will lead to an uninterrupted field of vision.
Meanwhile, disruptive clouds may obscure the sun across much of the Pacific Northwest, Deep South and East Coast.
People that cannot see the Mercury transit for themselves due to poor weather can watch the event live on AccuWeather.com.
Folks that miss Monday’s event will have to wait more than a decade for the next opportunity to see a Mercury transit, with the next one taking place on Nov. 13, 2032.
There is an even longer wait for the next Venus transit, which is sometimes referred to as a “twice in a lifetime event.”
Venus transits come in pairs that are separated by an extended period of time. Most recently, there were a pair of Venus transits on June 8, 2004, and June 5, 2012, with the next pair not taking place until Dec. 10, 2117, and Dec. 8, 2125.
This composite image of observations by NASA and the ESA's Solar and Heliospheric Observatory shows the path of Mercury during its November 2006 transit. (Solar and Heliospheric Observatory/NASA/ESA via AP)
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What you need to know for Monday’s rare Mercury transit, including the cloud forecast
By Brian Lada, AccuWeather meteorologist
Published Nov 5, 2019 5:39 PM EDT
Grab your telescopes and get some solar filters ready. A rare transit of Mercury across the sun will occur on Nov. 11. This rare astronomical event won't happen again until 2032, so don't miss out!
One of the biggest astronomy events of the year will take place at the start of this week. It's an event so rare that it won’t happen again until 2032.
On Monday, Nov. 11, people across North America, South America, Europe, Africa and western Asia will be able to see Mercury pass directly between the Earth and the sun in an astronomical alignment known as a transit.
Transits happen only a few times per century and provide a unique opportunity to see a planet glide across the face of the sun.
People will have a few hours to observe the event, which starts at 7:35 a.m. EST and lasts until 1:04 p.m. EST.
The planet Mercury is seen in silhouette, lower left of image, as it transits across the face of the sun, Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania. Mercury passes between Earth and the sun only about 13 times a century, with the previous transit taking place in 2006. Photo Credit: (NASA/Bill Ingalls)
Similar to a total solar eclipse, spectators will need a solar filter to shield their eyes from the harmful rays from the sun. Looking at the sun without a solar filter can lead to permanent eye damage and, in some cases, blindness.
However, onlookers will need more than just a solar filter to see the Mercury transit.
“Because Mercury is so small from our perspective on Earth, you'll need binoculars or a telescope with a Sun filter to see it,” NASA said.
It is imperative to have a certified solar filter on the part of the telescope where light enters. Wearing solar filters, such as solar eclipse glasses, and looking into the eyepiece of a telescope that is not outfitted with a filter of its own can still lead to irreversible eye damage.
The American Astronomical Society (AAS) says that the filters should comply with the ISO 12312-2 international safety standard. This number should appear with the filter’s original packaging or on the filter itself.
“Filters that are ISO 12312-2 compliant not only reduce visible sunlight to safe and comfortable levels but also block solar UV and IR radiation,” the AAS explained on their website.
NASA is showing people what happens if you look through a telescope or binoculars that does not have the proper solar filter. “Thanks to Vince Patton for this demonstration of what happens if you combine eclipse glasses and binoculars. Remember melting things in the sun with magnifying glasses? Don't let that be your eye!” (NASA/Vince Patton)
People will need not only the right equipment to see the Mercury transit but also cloud-free weather.
The best viewing conditions will be across the north central and southwestern United States where clear skies will lead to an uninterrupted field of vision.
Meanwhile, disruptive clouds may obscure the sun across much of the Pacific Northwest, Deep South and East Coast.
People that cannot see the Mercury transit for themselves due to poor weather can watch the event live on AccuWeather.com.
Folks that miss Monday’s event will have to wait more than a decade for the next opportunity to see a Mercury transit, with the next one taking place on Nov. 13, 2032.
There is an even longer wait for the next Venus transit, which is sometimes referred to as a “twice in a lifetime event.”
Venus transits come in pairs that are separated by an extended period of time. Most recently, there were a pair of Venus transits on June 8, 2004, and June 5, 2012, with the next pair not taking place until Dec. 10, 2117, and Dec. 8, 2125.
Related:
This composite image of observations by NASA and the ESA's Solar and Heliospheric Observatory shows the path of Mercury during its November 2006 transit. (Solar and Heliospheric Observatory/NASA/ESA via AP)