sqishy
May 7th, 2016, 11:03 AM
A transit of the planet Mercury across the Sun will take place this Monday, the most recent transit of any planet being that of Venus in June 2012.
It will start at 11:12 UTC* and end at 18:42, the middle of it being at 14:57 when Mercury gets close-ish to the center of the Sun's disk.
Here's the chance of viewing for wherever you are (weather-permitting):
http://eclipsewise.com/oh/oh-figures/tm2016-Fig02b.gif
Here's what you will see over time, if you can (only the pic above shows so just use the link):
http://eclipsewise.com/oh/oh-figures/tm2016-Fig01b.gif
As with solar eclipses but being even more important here (because transits are essentially extreme versions of annular eclipses), I'm going to say the sort of small print that should not be small:
DO NOT LOOK AT THE SUN DIRECTLY WITHOUT PROPER PROTECTION!
If you can see this event and want to see it directly, use proper sun viewing glasses or filters (not sunglasses!), and only those. Don't ever use a telescope to directly look even with those on either. If you don't have viewing glasses, astronomy shops should have them, or relevant trusted relevant websites for delivery, etc.
Here ends the hopefully-not-discouraging important part.
Indirect viewing is recommended as most ways of doing it give a bigger image to work with, and you won't be setting your eyes in the angle of the Sun; binoculars or telescopes can be used for this.
Here's the relevant information you need to know on this, it's in the wiki page on solar eclipses but as I said this is essentially the same thing:
https://en.wikipedia.org/wiki/Solar_eclipse#Partial_and_annular_eclipses
Because Mercury is both smaller than Venus and further away from us, its apparent width will be almost a fifth of Venus'.
To give some of a taste as to the actual thing, this is from the 2006 transit:
https://en.wikipedia.org/wiki/Transit_of_Mercury#/media/File:Mercury_transit_2.jpg
Mercury is the dot down-right from the center. This is of course not what it actually looks like, as the Sun's brightness is toned down massively.
Though it looks not to be much for some, it's a good reminder of how we are on the near-frozen edge of a tiny speck of rock, viewing another even tinier speck of rock that is having its far side be radiated by a colossal ball of plasma, with both of us falling around it, in a mostly empty void. Keep that in mind if you do go out to see this transit. There's a lot going on out there.
The last time Mercury has crossed the Sun for us was in November 2006. When the transits happen, it's in May or November due to certain celestial mechanics, but he interval between one November transit and the next November transit may be 7, 13, or 33 years, and the interval between one May transit and the next May transit may be 13 or 33 years.
The next time this will happen is in November 2019. Sure, it's earlier than 2117 for the next Venus transit, but 3 years is a long time, and we don't have many opportunities like this.
*UTC is Coordinated Universal Time, which is a global time standard that is the same time for GMT 0 when not in daylight savings time in summer, so keep that in mind. Basically, everyone in the UK's timezone will have the event happen 1 hour later than it says on UTC for this.
That is all (just please don't burn your eyes).
It will start at 11:12 UTC* and end at 18:42, the middle of it being at 14:57 when Mercury gets close-ish to the center of the Sun's disk.
Here's the chance of viewing for wherever you are (weather-permitting):
http://eclipsewise.com/oh/oh-figures/tm2016-Fig02b.gif
Here's what you will see over time, if you can (only the pic above shows so just use the link):
http://eclipsewise.com/oh/oh-figures/tm2016-Fig01b.gif
As with solar eclipses but being even more important here (because transits are essentially extreme versions of annular eclipses), I'm going to say the sort of small print that should not be small:
DO NOT LOOK AT THE SUN DIRECTLY WITHOUT PROPER PROTECTION!
If you can see this event and want to see it directly, use proper sun viewing glasses or filters (not sunglasses!), and only those. Don't ever use a telescope to directly look even with those on either. If you don't have viewing glasses, astronomy shops should have them, or relevant trusted relevant websites for delivery, etc.
Here ends the hopefully-not-discouraging important part.
Indirect viewing is recommended as most ways of doing it give a bigger image to work with, and you won't be setting your eyes in the angle of the Sun; binoculars or telescopes can be used for this.
Here's the relevant information you need to know on this, it's in the wiki page on solar eclipses but as I said this is essentially the same thing:
https://en.wikipedia.org/wiki/Solar_eclipse#Partial_and_annular_eclipses
Because Mercury is both smaller than Venus and further away from us, its apparent width will be almost a fifth of Venus'.
To give some of a taste as to the actual thing, this is from the 2006 transit:
https://en.wikipedia.org/wiki/Transit_of_Mercury#/media/File:Mercury_transit_2.jpg
Mercury is the dot down-right from the center. This is of course not what it actually looks like, as the Sun's brightness is toned down massively.
Though it looks not to be much for some, it's a good reminder of how we are on the near-frozen edge of a tiny speck of rock, viewing another even tinier speck of rock that is having its far side be radiated by a colossal ball of plasma, with both of us falling around it, in a mostly empty void. Keep that in mind if you do go out to see this transit. There's a lot going on out there.
The last time Mercury has crossed the Sun for us was in November 2006. When the transits happen, it's in May or November due to certain celestial mechanics, but he interval between one November transit and the next November transit may be 7, 13, or 33 years, and the interval between one May transit and the next May transit may be 13 or 33 years.
The next time this will happen is in November 2019. Sure, it's earlier than 2117 for the next Venus transit, but 3 years is a long time, and we don't have many opportunities like this.
*UTC is Coordinated Universal Time, which is a global time standard that is the same time for GMT 0 when not in daylight savings time in summer, so keep that in mind. Basically, everyone in the UK's timezone will have the event happen 1 hour later than it says on UTC for this.
That is all (just please don't burn your eyes).