How dark does the sky get during totality?
During a total eclipse of the Sun the entire photosphere of the Sun is blocked out. So, it’s obviously going to impact the brightness of the sky.
The Moon’s shadow is only about 100 miles across so while you are experiencing totality the sky above you will not be as dark as night.
It is said that the sky appears as it would at twilight or as it would appear an hour after sunset.
What planets are on display?
There are 5 planets that are bright enough to view with the naked eye. Although planets don’t emit light they reflect the Sun’s light and some of the planets appear brighter than the stars in the sky.
The planet’s that will be visible in the sky at the time of the eclipse are:
- Venus (magnitude -4.0)
- Jupiter (magnitude -1.8)
- Mars (magnitude +1.8)
- Mercury (magnitude +3.3)
Jupiter will not be visible for those viewing the eclipse in Oregon as it will be below the horizon.
Mercury may not be bright enough to pick out, it is close to the limit of what you can see with the naked eye and your eyes may not have adjusted enough.
There is a possibility of seeing 7 of the main players in our solar system in the same view. Not bad! (The 7th is the Earth you’re standing on)
Will I see the stars?
There are a couple of candidate stars that will be bright enough to stand out in the sky during totality.
- Sirius (magnitude -1.4)
- Regulus (magnitude +1.3)
Sirius is the brightest star in our skies, so it’s not surprising that it will be making an appearance during the eclipse.
Regulus is the brightest star in the Leo constellation and will be close to the left of eclipsed Sun.
It is possible that you will see some more stars in the sky but Sirius and Regulus will really stand out.
Why would I look at anything other than the corona?
Good point! Don’t get distracted from the main event but you might want to look around too for a few moments.
But after the anticipation, you will be forgiven for only having your eyes on the main prize!
Useful links: