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Questions tagged [venus]

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

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Why have some space exploration breakthroughs not been retried for the last 50 years?

The last successful probe to land on Venus was Venera 10, 1975. There was also Venera 11 & 12 shortly after, but both experienced camera failures or multiple instrument failures. Why haven't we ...
Ethan's user avatar
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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
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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
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4 votes
4 answers
5k views

What is the ring of light around the moon and which star seen near it?

In this amatuer photograph, the following are to be noted: There is a faint ring of light around the moon. What is the distance we see this at. From the ground it looks like a hundred meters. There ...
Nick's user avatar
  • 239
3 votes
1 answer
95 views

Does the reflected light from Earth boost Venus' apparent magnitude when it is seen transiting the Sun?

During solar transits of Venus as seen from Earth, exactly 0% of Venus' disk is illuminated by sunlight, as expected. However during these transits, Earth is at opposition and fully illuminated by the ...
user267545's user avatar
1 vote
1 answer
223 views

How close can Venus be to the sun in the sky and still be visible to the naked eye?

Assuming no artificial light, what is the minimum number of degrees apart would the sun and Venus have to be during the beginning of civilian twilight for the planet to be visible to the naked eye to ...
Bob516's user avatar
  • 1,489
5 votes
2 answers
930 views

Is Venus in our sun's habitable zone?

I know that Venus is closer to the sun than Earth and if an article I read is to be believed, Venus is hotter than Mercury even though the latter is closer to the Sun. The explanation for this odd ...
Hudjefa's user avatar
  • 353
3 votes
1 answer
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When did Venus get as hot as it is now?

My previous question turned out to not ask the question I thought I was asking. I have read that Venus began its heating-up around 700-750 million years ago. When did the Venusian atmosphere get ...
Michael Bonnet's user avatar
4 votes
1 answer
109 views

When did Venus reach approximate radiation equilibrium?

I have read that Venus is roughly at radiation equilibrium - that is, heat out is approximately equal to heat in. I have also read that Venus began its heating-up around 700-750 million years ago. My ...
Michael Bonnet's user avatar
3 votes
1 answer
98 views

Is Venus' magnetosphere actually more powerful than the solar wind's magnetic field that induced it or vice versa?

Is the Venusian magnetic field actually more powerful than the solar wind's magnetic field that induced it? I know that Venus' magnetic field is not due to Magnetohydrodynamic processes rather, it is ...
Arjun's user avatar
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1 answer
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3rd brightest ever object in the sky

What’s the 3rd brightest ever recorded object in the sky? For example Venus is normally the 3rd brightest object in the sky. However there have been the occasional comet or Supernova that have ...
blademan9999's user avatar
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
4 votes
3 answers
679 views

How do the phases of Venus prove heliocentrism?

I have been doing research about the Copernican Revolution, and one of the main arguments that caused many astronomers to change their minds was Galileo's observation of all phases of Venus. The proof ...
fartgeek's user avatar
  • 161
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
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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
4 votes
1 answer
126 views

See Venus in daylight

At what distance (in angular degrees) from the Sun, could we see Venus, in mid daylight, with a pair of binoculars (7x50)?
Jacquelin Hardy's user avatar
2 votes
0 answers
80 views

Are stagnant-lid Earth analogues guaranteed to become Venus-like?

In our current understanding of Venus, two things are generally accepted: Venus reached its thermal tipping point at least 700 Ma. As the Sun's luminosity gradually increased with age, its average ...
Thoth's user avatar
  • 181
3 votes
2 answers
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Is there a term for a Venus visibility period

Is there a term for the period of time when Venus is first visible in the evening to when it switches to being the "morning star", or vice versa? For example, as depicted in the image below,...
Greg Miller's user avatar
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2 votes
0 answers
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How could we detect if Venus or mars were being terraformed by aliens? [closed]

If any other body in our solar system was being terraformed by aliens, what would be the ways in which we would detect this? Initially I thought of Venus or mars but I guess this could extend to any ...
Darth Scitus's user avatar
2 votes
0 answers
124 views
+400

Has "crescent-twinkling" even been demonstrated or at least calculated/predicted? Any "twinkleometer" data for Venus out there?

My new answer to Why does Venus flicker? addresses something that I find particularly interesting; Venus can be an incredibly thin crescent at times, and even a 1 arcminute large thin ring with an ...
uhoh's user avatar
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6 votes
1 answer
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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
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
1 vote
0 answers
76 views

How bright does Venus appear from the moon if it replaced Earth?

If you were standing on the moon, Earth will appear mostly around -17.7 at maximum brightness. However, since Venus has a higher albedo than Earth, Venus would be brighter. What would be Venus's ...
InfinitySwordofDiamond's user avatar
2 votes
1 answer
96 views

How would the synodic period of Venus appear to change if both planets were moved 10 million additional miles away from the Sun?

Let us say that Earth and Venus are both moved 10 million additional miles from the sun. How would the synodic period of Venus appear to change for an observer on Earth? If 584 days is Venus' current ...
JM Yaden's user avatar
  • 171
2 votes
0 answers
127 views

Eastern star at night 2022 July 10 [closed]

What is the star in the eastern sky tonight with a moon or planet at the 7 o’clock position?
Barry Barker's user avatar
4 votes
2 answers
131 views

What stars am I seeing in the daytime?

I currently live in the United Kingdom, in an area where the overall elevation is high so while the hills are rolling rather than peaky, they are all well above sea-level. A few weeks ago I was on a ...
Wookie's user avatar
  • 143
5 votes
0 answers
288 views

Why aren't there sulfuric acid seas on Venus?

It's commonly known that sulfuric acid rain doesn't reach Venus' surface. It evaporates instead because the surface it too hot. But considering how high the pressure at the surface (9.3 MPa), shouldn'...
Prido1024's user avatar
2 votes
2 answers
537 views

Could a magnetosphere be created for Venus by recreated by spinning-up the planet to a 24 hour day?

If Venus in it is current state, started rotating at the same rate as Earths 24hrs rotation, would it develop a magnetic field of roughly the same strength as Earth's? If so, would that help in any ...
eBookworm's user avatar
  • 145
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
5 votes
1 answer
395 views

Would a system consisting of Earth and Venus orbiting around a common center be stable in the long-term?

Earth and Venus and very close to each other in mass and would both orbit around a point in space positioned almost perfectly in between the two. Assume that this system is 1 AU from the Sun and the ...
user177107's user avatar
  • 2,699
3 votes
2 answers
151 views

Which Venus scientists discovered the hole in the ozone layer?

After 21:00 in Venus: Earth’s Evil Twin or Just Misunderstood? (live public talk) from the JPL YouTube channel the person being interviewed "Sue Smrekar, Rocky ...
usernumber's user avatar
  • 17.6k
3 votes
2 answers
179 views

When can Moon occult Venus?

I'm trying to solve this task: At what age of the Moon (in days after the new moon) is it possible for the Moon to occult Venus? How I was solving it: Angular velocity of the Moon is 13.2 degrees ...
ALiCe P.'s user avatar
  • 1,017
2 votes
1 answer
139 views

What discoveries were made thanks to Pioneer orbiter data?

Based on the Wikipedia page Pioneer Venus Orbiter (also known as Pioneer Venus 1, Pioneer 12, 1978-051A) there were quite a few scientific instruments on board. But what scientific results were ...
usernumber's user avatar
  • 17.6k
2 votes
0 answers
69 views

More on NASA's "blockbuster return to Venus" and what is in for astronomy?

On June 2nd, 2021, I read an Science-article with the click-baiting title Venus can’t wait—NASA plans blockbuster return to hothouse neighbor which mainly refers to a NASA press release from the same ...
B--rian's user avatar
  • 5,626
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
3 votes
2 answers
175 views

Why can't ptolemaic Venus be fully lit?

In wikipedia's article on the phases of Venus it says: The Ptolemaic system would never allow Venus to be fully lit from the perspective of the Earth, as this would require it to be on the far side ...
Erik Vesterlund's user avatar
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
  • 30.7k
5 votes
2 answers
267 views

Solar wind, Earth wind and planetary winds?

In February 2021, a new form of "electrified gas breeze" was announced, see blog by Tony Phillips entitled A New Form of Space Weather: Earth Wind which might a possible explanation for ...
B--rian's user avatar
  • 5,626
3 votes
0 answers
86 views

Measured values of the solar irradiance at other values than 1 AU?

It is straight forward to estimate the total solar irradiance of a planet using the Earth's solar constant, and scaling it according to the (mean) distance of the planets. But for which planets have ...
B--rian's user avatar
  • 5,626
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
2 votes
1 answer
371 views

Moment of inertia factor of Venus and Pluto

Wikipedia's Moment of inertia factor begins: In planetary sciences, the moment of inertia factor or normalized polar moment of inertia is a dimensionless quantity that characterizes the radial ...
Majoris's user avatar
  • 545
3 votes
2 answers
220 views

What does the amino acid found in the atmosphere of Venus mean?

An amino acid is a part of DNA, but it has only been found on Earth. Is the amino acid maybe from one of the space vehicles that has orbited, scanned, or surveyed Venus? How can a part of DNA survive ...
Jenny's user avatar
  • 31
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
1 vote
1 answer
277 views

Launch windows for Venus transit; how to convert heliocentric longitudes to date?

Being a bit familiar with celestial mechanics, I know that the Hohmann transfer orbit is the quickest way to transfer between two circular orbits of different radii around a central body in the same ...
B--rian's user avatar
  • 5,626
1 vote
0 answers
107 views

Characteristics of Venus' jet streams?

Since the Voyager missions, the atmosphere of Jupiter received great attention, its jet streams made it into text books on geofluid mechanics, including their characteristics like the how they meander,...
B--rian's user avatar
  • 5,626
1 vote
0 answers
59 views

Observed meteors on Venus?

In an article on Venus by JPL from 1996 I read Due to the dense Venusian atmosphere, primary impact craters of less than a 3 kilometer (2 mile) diameter are nonexistent. I am now wondering whether ...
B--rian's user avatar
  • 5,626
1 vote
0 answers
625 views

Background radation on Venus?

Venus is often refered to as Earth-twin, simply because of its similar size. In the very hypothetical case of a human mission to Venus, and leaving the all other challenges of Venus toxic atmosphere ...
B--rian's user avatar
  • 5,626
8 votes
1 answer
458 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
0 votes
1 answer
255 views

An influx of water on Venus

What if a moon like triton or a frozen extraterrestrial body containing lots of frozen ice were set on a collision course with Venus. Would an inlfux of huge amounts of H2O precipitate a possible ...
David Leduc's user avatar
1 vote
0 answers
38 views

Are there any ALMA or JCMT detections of extraterrestrial phosphine that have been confirmed by direct sampling?

Please note that I am not a professional astronomer but an interested layman. I've informed myself on the matters below by perusing arXiv--there are likely other publicly-accessible primary sources I ...
223seneca's user avatar
  • 111