Skip to main content

Questions tagged [venus]

Questions regarding the planet Venus, the second planet from the Sun.

Filter by
Sorted by
Tagged with
57 votes
2 answers
5k views

Why has Venus's atmosphere not been stripped away by solar wind?

This answer on Space Exploration to a question about Mars says that one reason Mars has such a thin atmosphere is because it lacks a magnetic field to protect it from the effect of double solar winds. ...
called2voyage's user avatar
  • 6,290
44 votes
3 answers
45k views

Why did Venus not lose its atmosphere without a magnetic field?

It is often stated that the magnetosphere not only shields the planet from cosmic radiation, but also prevents atmospheric loss. Why then did Venus not lose most of its atmosphere if it doesn't have a ...
Irigi's user avatar
  • 1,142
39 votes
3 answers
20k views

Is Venus in some way tidally locked to... Earth?

The video here demonstrates how Earth sees the same face of Venus every inferior conjunction (i.e., two planets are the closest to each other): https://www.youtube.com/watch?v=4m_ouMC61-w (or https://...
puzzlet's user avatar
  • 499
36 votes
2 answers
6k views

How was the mass of Venus determined?

The mass of Venus seems rather complicated to determine to me: Venus doesn't have any satellites, so you can't just apply Kepler's third law (like you would with Jupiter or Saturn for instance) to ...
usernumber's user avatar
  • 17.6k
31 votes
2 answers
5k views

What is the current accepted theory as to why Venus has a slow retrograde rotation?

According to this NASA overview, the planet Venus is unique (amongst the major planets), Venus has a slow retrograde axial rotation, taking 243 Earth days to make one rotation (which is longer than ...
user avatar
24 votes
2 answers
5k views

Can the Moon eclipse Venus?

The title basically says it all. As seen from the Earth, is it possible for the Moon to eclipse Venus (or any other planet) or are the orbits inclined such that this never happens? If such an eclipse ...
CatchAsCatchCan's user avatar
21 votes
6 answers
5k views

Why doesn't the IAU definition of "Planet" disqualify Mercury and Venus as planets?

Here's the IAU definition of a planet (source): A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ...
Schroeder's user avatar
  • 511
21 votes
2 answers
7k views

Why is Venus's atmospheric pressure 75 times that of earth when carbon dioxide is only 1.5 times heavier than air?

Obviously I have forgotten by basic college chemistry. I am getting carbon dioxide at 1.87kg per cubic meter and compared it to nitrogen and oxygen but source says carbon dioxide is 1.5 times heavier ...
Sedumjoy's user avatar
  • 1,201
19 votes
4 answers
5k views

Is the Earth going to evolve towards Mars' fate or Venus' fate?

Upon reading on this site (and many others), one can think that Mars might have supported life in a distant past (discovery of liquid water, valleys, mountains...). On the other hand, Venus is the ...
Nico's user avatar
  • 803
19 votes
4 answers
16k views

If Venus and Mars changed places, would we then have 3 habitable planets?

This is the supposition: Venus is too hot, Mars is too cold. If they switched places then Solar energy would change to make both more Earth-like. We might as well have had three instead of just one &...
LocalFluff's user avatar
  • 11.4k
18 votes
2 answers
2k views

Why haven't Earth and Venus got any tiny moons? Or have they?

Why haven't some meteoroids gotten caught in Earth's or Venus' orbit? AFAIK most meteors are tiny fragments from comets. Shouldn't some comet tail sometime have passed Earth orbit at velocities ...
LocalFluff's user avatar
  • 11.4k
15 votes
2 answers
3k views

Why is it impossible to infer the surface temperature of Venus by spectroscopy observation from earth?

It is well known that the surface temperature of the sun is determined by fitting the sunlight with the black-body spectrum. Why is this inappropriate for Venus? I have the question because of the ...
S. Kohn's user avatar
  • 879
15 votes
2 answers
3k views

How could Mars' atmosphere be shed by solar winds, when Venus has a thick atmosphere despite no magnetic field?

Our current understanding of how Mars lost its atmosphere is because it lost it magnetic field, due to a barrage of reasons, such as core cooling due to low volume and cooling off quickly. This ...
Alastor's user avatar
  • 2,668
12 votes
2 answers
965 views

Could Venus be a source of Earth's apparent overabundance of water?

I've watched documentaries about the solar system, where it is suggested that Venus once had oceans of liquid water similar to those that cover most of Earth today. Venus is now in a period of ...
db9dreamer's user avatar
12 votes
1 answer
1k views

Mars vs Venus: the retention of atmospheres in relationship to Earth

Correct me if I'm wrong, but the factors than enable a planet to retain or lose an atmosphere seem to be: 1. Magnetic Field, 2. Solar Winds, 3.Weight of Gases, 4. Planetary Temperatures. 5. Distance ...
Peter Wilson's user avatar
12 votes
1 answer
2k views

Explanation for the mathematics behind Venus' retrograde motion

I've always been interested by the pattern within Venus' orbit around the sun. I found this image and formula of its retrograde motion in the upper right hand corner which confused me. What does it ...
AppleFix88's user avatar
11 votes
3 answers
4k views

Is Venus' north towards Earth's south

Is Venus upside down? Does its north point in the same direction as Earth's south? (roughly) Or does it just spin clockwise and its north points towards Earth's north? (also roughly) It seems that the ...
Stephen's user avatar
  • 383
11 votes
2 answers
5k views

What would happen if Venus and Earth collided?

The first thing we would need to consider is that Earth has already been hit by a protoplanet half its size 4.5 billion years ago, meaning the Earth may have a chance of staying intact after the ...
user avatar
11 votes
2 answers
2k views

Are there ever any simultaneous transits of both Mercury and Venus as seen from the Earth?

Transits of Mercury happen fairly frequently due to its short period, but transits of Venus are less frequent. I've looked over the data available to me and found that there have been transits of ...
Cyberherbalist's user avatar
11 votes
2 answers
809 views

Could an impact have resurfaced Venus 300 million years ago?

Venus surface isn't older than about 300 million years. The only explanation I've come across is that some kind of global volcanism resurfaced the planet. But couldn't it have been an impact event? A ...
LocalFluff's user avatar
  • 11.4k
11 votes
1 answer
4k views

Is it possible that Mercury was originally the moon of Venus after a giant impact?

Mercury looks like the Moon, and so it makes me think about a question: is it possible that Venus and Mercury were the a same planet originally, and a giant impact with that planet made it split into ...
Gstestso's user avatar
  • 2,219
10 votes
1 answer
708 views

Why has the orbit of Venus such a low eccentricity?

The eccentricity of Venus is almost 14 times smaller than that of Mars, and 2.5 times smaller than that of Earth, and 30 times smaller than that of Mercury. Is it just a pure fluke? Or is there some “...
user avatar
10 votes
1 answer
1k views

How (the heck) was this photo of Venus at inferior conjunction (between us and the Sun) taken?

This great answer by @gerrit discussing planetary phases seen in visible light contains the image I've included below. According to the Wikimedia Commons link these are ESO images from the Venus ...
uhoh's user avatar
  • 30.6k
10 votes
2 answers
7k views

Has the conjunction between Venus, Jupiter, and Regulus only occurred twice in 2,000 years?

I recently heard the claim that mid-July, the "Star of Bethlehem" formed for the first time in 2,000 years, where the Star of Bethlehem is a three-way conjunction between Venus, Jupiter, and Regulus. ...
El'endia Starman's user avatar
9 votes
4 answers
9k views

How to calculate conjunctions of 2 planets

So, the recent conjunction of Jupiter and Venus seems to have spawned lots of excitement over this "rare" event. But what I can't figure out, is exactly how rare it is. And I've seen such conflicting ...
AdamMasters's user avatar
9 votes
2 answers
442 views

Can we find out whether early Venus was Earth-like or not?

It has been speculated that Venus billions of years ago could've had a much different atmosphere with liquid water on its surface and possibly life. Partly thanks to the cooler young Sun. But is it ...
LocalFluff's user avatar
  • 11.4k
8 votes
2 answers
709 views

How can it be known that Venus does not have plate tectonics?

This answer provides some insight into Venus' surface geology: Water may be necessary as a lubricant for plate tectonics. Whether or not this is the case, Venus does not have plate tectonics. It ...
uhoh's user avatar
  • 30.6k
8 votes
2 answers
1k views

Could Venus or Mercury have a moon that we haven't detected?

Let's consider Mars' two moons for a moment. They're small, not even spherical, and most likely are captured asteroids. They weren't discovered until the late 1800's. Telescopes are much more powerful ...
DrZ214's user avatar
  • 1,970
8 votes
1 answer
478 views

Has Hubble photographed Venus in near IR? If so how does it compare to the new and exciting Parker Solar Probe image?

Phys.org's Parker Solar Probe offers stunning view of Venus includes the image below taken by the Parker Solar Probe during it's most recent gravitational assist flyby of Venus as it continues to rid ...
uhoh's user avatar
  • 30.6k
8 votes
2 answers
238 views

Phosphine on Venus?

For the purposes of this question, let's assume that the team really have detected phosphine. My question is how do we know that phosphine is on Venus, and not closer to home? I've just found out a ...
DJL's user avatar
  • 181
8 votes
1 answer
2k views

What would happen if Venus was hit by a Chicxulub-like meteor?

What would happen if Venus was hit by a Chicxulub-like meteor? Would the dense atmosphere and high surface pressure and temperature lead to a different result compared to what happened here on Earth?
d-b's user avatar
  • 349
8 votes
1 answer
457 views

How long do thunderstorms on Venus last?

A while ago, I learned about field of exometeorology (the study of other planets ' atmospheres) which fascinates me. In particular, I read about thunderstorms on Venus, e.g. about the results from ESA'...
B--rian's user avatar
  • 5,626
8 votes
1 answer
207 views

Periodic behavior of Venus

After a couple months of watching a very bright Venus appear at dusk and set soon after the Sun, I've noticed that it seems to have temporarily disappeared to the naked eye. I used a virtual sky ...
David H's user avatar
  • 844
8 votes
1 answer
195 views

What are the prospects for follow-up observations of phosphine on Venus?

Today, it was officially announced that astronomers have detected phosphine on Venus via the $\text{PH}_3(0\to1)$ transition (Greaves et al 2020). While the line was found by both the James Clerk ...
HDE 226868's user avatar
  • 36.6k
7 votes
3 answers
25k views

Why does Venus flicker?

I was watching Venus with the naked eye yesterday at about 7 pm and I noticed that it was flickering, almost like a star. I have always learned that planets don't flicker to the naked eye, only stars ...
TomCho's user avatar
  • 390
7 votes
2 answers
3k views

Can we find rocks from Venus or Mercury on Earth?

As we know, we can find rocks from Mars on Earth, how about Venus and Mercury? Is that not found yet? Or it is impossible to find them because they are closer to the Sun, and debris won't go far away ...
Gstestso's user avatar
  • 2,219
7 votes
2 answers
462 views

Venus' magnitude during inferior conjunction

I was doing an assignment on Stellarium when I observed Venus to have an apparent magnitude that didn't become less negative than -3, even at inferior conjunctions when we faced the dark side of Venus....
Diaa Eldin Malek's user avatar
7 votes
1 answer
881 views

Effects of the solar tide on planets

It’s well known that (lunar) tides on Earth result in a transfer of angular momentum from Earth proper to the Earth–Moon orbital motion. That’s why the Moon resides now in a high Earth orbit, and ...
Incnis Mrsi's user avatar
7 votes
2 answers
245 views

Extraterrestrial snow?

What do we know about extraterrestrial snow? On which (exo)planets or (exo)moons do we have direct hints for its existance? This is indeed a children's question, but I struggle to answer it ...
B--rian's user avatar
  • 5,626
6 votes
2 answers
698 views

Why do the upper-atmosphere clouds of Venus appear to have that V shape?

IF I understand correctly, the atmosphere moves in the same direction as the rotational spin, but about 60 times faster. It is driven from the hot side of Venus to the cold side (the difference being ...
Bruce's user avatar
  • 93
6 votes
2 answers
1k views

Why does Earth have a dip in the CO2 absortion spectrum from 14 to 16 micron?

This paper shows that there is a dip in the CO2 absorption spectrum of Earth. In essence the trough of the absorption of CO2 for Earth is cut into two separate troughs instead of 1 large trough. Why ...
a.t.'s user avatar
  • 183
6 votes
3 answers
336 views

Can lunar occultation of Venus occur during solar eclipse?

Moon can occult Venus. Venus can transit across the solar disc. Moon can elipse Sun. Can all three celestial events occur at the same time - Moon is at front of Sun (partial eclipse is fine) and Venus ...
Leos Ondra's user avatar
  • 1,074
6 votes
1 answer
182 views

Does anybody know how to solve this Earth-Venus-Sun problem?

How can I find (in terms of the angle) the moment when in the system Sun-Earth-Venus, Venus can be seen the most bright if its brightness (flow received in Earth) is proportional to the size projected ...
Miguel Gutiérrez's user avatar
6 votes
1 answer
635 views

Why Venus evolved so differently from Earth?

I read somewhere that the reason why Venus has a runaway greenhouse effect and Earth doesn't is the former's inability to form separate tectonic plates due to slightly higher temperature softening the ...
Meatball Princess's user avatar
6 votes
1 answer
631 views

How are sulfuric acid clouds able to completely cover Venus?

It is a well-known fact that an opaque layer of highly reflective clouds of sulfuric acid completely shrouds Venus preventing its surface from being seen from space in visible light. This is mentioned ...
Nilay Ghosh's user avatar
  • 4,694
6 votes
2 answers
229 views

Are the Venusian "continents" likely to have existed before the global resurfacing event?

A topographic map of the surface of Venus shows the large highland areas Ishtar Terra, Aphrodite Terra and Lada Terra that have occasionally been described as "continents", plus various ...
user avatar
6 votes
1 answer
594 views

Does light from the sun reach the surface of Venus

I am aware we have images from the surface of Venus from the Venera missions but I am not sure if those images are taken using the visible spectrum the human eye can see. This is why I was wondering ...
Max Young's user avatar
  • 175
6 votes
1 answer
217 views

When do Mercury/Venus reach greatest elevation at sunset/twilight for a given location?

On what day does Mercury reach its greatest elevation (in degrees from the horizon) at sunset a given location? The obvious answer is the day of Mercury's greatest elongation from the Sun, but, ...
user avatar
6 votes
0 answers
226 views

Did simultaneous transits of Mercury and Venus actually last occur in 373,173 BC?

According to the Wikipedia article for Transit of Venus, the last time a transit of Mercury and a transit of Venus occurred at the same time was 22 September of 373,173 BC. This is a Featured Article ...
Johansson McFleppers's user avatar
5 votes
2 answers
988 views

Why is Jupiter called so?

I have read before that Jupiter is named after the great Roman god because of how bright it is. I can't help but wonder, why wasn't the name given to Venus instead? Isn't Venus much brighter than ...
Abdul Alhazred's user avatar