# So much for Mars - how about Venus? **URL:** \ **Category:** Factual Questions\ **Created:** [August 29, 2003, 9:55pm UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523 "2003-08-29T21:55:50Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [August 29, 2003, 9:55pm UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/1 "2003-08-29T21:55:50Z")
[This](http://www.astronomysight.com/as/info/planets/venus.html) page says Venus’s closest approach to Earth (perigee?) is 25,700,000 miles. When will this happen? Will it look any different or more impressive than it already does? ---
**Author:** ![shelbo](https://avatars.discourse-cdn.com/v4/letter/s/3d9bf3/32.png) [@shelbo](https://boards.straightdope.com/u/shelbo)\ **Post date:** [August 29, 2003, 10:30pm UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/2 "2003-08-29T22:30:21Z")
At its very closest, Venus is directly between the Earth and the Sun. Makes viewing difficult without sunglasses. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [August 29, 2003, 10:45pm UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/3 "2003-08-29T22:45:46Z")
June 08 2004 is when the next transit of Venus occurs; by the way, ordinary sunglasses will definitely not be good enough protection against the sun’s rays. It is a good opportunity to see a planet the same size as the Earth in front of our local star, and get an idea just how small our world is. * * * SF worldbuilding at [http://www.orionsarm.com/main.html](http://www.orionsarm.com/main.html) ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [August 30, 2003, 3:14am UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/4 "2003-08-30T03:14:09Z")
Note that at inferior conjunction, Venus’ dark side will be facing Earth. And when Venus is “full”, it is on the opposite side of the Sun, with the Sun obscuring things again. Venus is in fact brightest when it is a [thickish crescent](http://www.racingshadow.com/planets/Venus/VenusGallery.html) and somewhat from it’s closest. Note that transits of Venus are quite rare. No one alive have ever seen one. Inferior conjuctions, when Venus is at it’s closest, occur about every 584 days. Like with Mars, some are closer than others. There may are may not be a transit at such a conjuction. ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [August 30, 2003, 4:09am UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/5 "2003-08-30T04:09:08Z")
Venus is a lousy target in a telescope anyway; its cloudy surface betrays very little detail and it has no moons to watch. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [August 31, 2003, 1:20am UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/6 "2003-08-31T01:20:18Z")
To the contrary **RickJay** : It’s a really beautiful crescent, even in my low power scope. It’s so bright and smoothly shaped. ---
**Author:** ![Theios](https://avatars.discourse-cdn.com/v4/letter/t/e8c25b/32.png) [@Theios](https://boards.straightdope.com/u/Theios)\ **Post date:** [September 1, 2003, 8:14am UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/7 "2003-09-01T08:14:41Z")
> [@](#): > > \*Originally posted by eburacum45 \* > \*\*June 08 2004 is when the next transit of Venus occurs; > by the way, ordinary sunglasses will definitely not be good enough protection against the sun’s rays. > > It is a good opportunity to see a planet the same size as the Earth in front of our local star, > and get an idea just how small our world is. > > \*\* So, if you had one of those special solar filters for your telescope, would this be something cool to see? When would the next one be? And do you think this would work with my gf as justification to get a solar filter for my scope? ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [September 1, 2003, 9:21am UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/8 "2003-09-01T09:21:38Z")
> [@](#): > > \*Originally posted by Theios \* > **So, if you had one of those special solar filters for your telescope, would this be something cool to see?** Definitely. Note that it’s not visible from western US. Eastern US gets a partial view (transit ends just after sunrise), and Europeans get to see the whole thing. Take a look at the maps on [this page](http://sunearth.gsfc.nasa.gov/eclipse/transit/venus0412.html). > [@](#): > > **When would the next one be?** 1. The above link has some info on that too. > [@](#): > > \*\* And do you think this would work with my gf as justification to get a solar filter for my scope? \*\* Sure, but only if you can make sure she doesn’t learn about the [projection](http://www.eclipse-chasers.com/safe.htm) method. ---
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [September 1, 2003, 3:13pm UTC](https://boards.straightdope.com/t/so-much-for-mars-how-about-venus/198523/9 "2003-09-01T15:13:41Z")
> [@](#): > > \*Originally posted by ftg \* > \*\*Note that at inferior conjunction, Venus’ dark side will be facing Earth. And when Venus is “full”, it is on the opposite side of the Sun, with the Sun obscuring things again. Venus is in fact brightest when it is a [thickish crescent](http://www.racingshadow.com/planets/Venus/VenusGallery.html) and somewhat from it’s closest. Because the two effects are complementary (closeness, dark side phase), the brightness of Venus hardly varies. Except for the few days it displays almost no sunlit portion, when it is closest to Earth, Venus is just about magnitude -4, plus a little, minus no more than a magnitude.