Albedo Definition and 24 Threads

My heroes have found a barely-tolerable 'greenhouse' planet, the upper part of a vast volcanic shield having acceptable temperature and pressure (*). The anoxic atmosphere is N2+CO2, but holds enough H2O for nightly dew near the summit. So, can condense that, use for hydroponics, irrigate...

Hi all, In the Jovian system, Callisto is extremely dark (albedo 0.22) because its ancient surface is covered with meteoritic dust. Ganymede is brighter (albedo 0.43) as its surface has been resurfaced more recently and hasn't had as much time to accumulate dust; that's confirmed by the younger...

I live near some highways that are roughly "a couple of miles" away. On some blessed days they are inaudible, and on other days they roar with a low frequency sound that penetrates into every corner of the basement. (If frequency matters, it would be most preferable to refract sound at 20Hz...

As mentioned above, I wanted to devise an equation that can relate the colour of a surface to the temperature on the surface. I tried using the general definition of albedo and combining it with the Stefan-Boltzmann equation (see above, Relevant Equations). However this means that the higher the...

tau Ceti 'f' is an *interesting* planet, on habitable zone's outer border-line around a mostly placid, mid-K star, its Sine(i) mass highly sensitive to orbital plane alignment. IIRC, current estimates are based on the big asteroid belt's ~35º inclination to line-of-sight. With necessary...

Hi! I have read that cometary nuclei have a very low albedo, even lower than coal or asphalt. Because of this, they absorb lots of light and heat rather than reflecting them. So I was wondering how hard is it to detect extinct comets. Could the solar system be full of dead nuclei buzzing around...

I have a question regarding the relationship between the reflectance and albedo of a material. What I Know: Both quantities are the ratio between the incoming and outgoing radiation from a material. Correct me if I am wrong, the reflectance of a material depends on the material while the albedo...

Homework Statement We consider a planet in a circular orbit around a star. I have to calculate the average temperature knowing that the radius of the orbit is 0.4 AU and that the planet reflects 30% of the incident light Homework EquationsThe Attempt at a Solution I used this equation F = L/4...

The reason I am making this thread is because I have a question regarding predicted temperatures of planets based on their area, distance from the sun, and albedo. Going by the planetary equilibrium temperature, T4 = [L(1-a)]/(16σπD2), I have seen numerous websites state that Venus would...

This has been asked already, but it was either answered incorrectly or I'm just not understanding it right. I was under the impression that albedo is the ratio of radiation reflected off a body compared to the total incident on that body. Hence black bodies have an albedo of 0 and more...

I have a three part question: Background: For a planet on an orbit with semi-major axis a and eccentricity e, the distance of closest approach to the Sun is r = a(1 − e) and the farthest approach is r = a(1 + e). (1) Assuming an albedo A = 0.2, estimate the temperature on Earth in equilibrium...

Homework Statement The presence of a huge ice sheet helps support itself by changing the amount of energy the Earth receives.Question 13 options: True False Homework Equations none The Attempt at a Solution Ice sheets have high albedo, therefore Earth gets less solar energy?

Homework Statement Assume that a planet can have an atmosphere if the escape speed of the planet is 6 times larger than the thermal speed of the molecules in the atmosphere (also known as the root-mean-square molecular velocity). Suppose a hypothetical object having the same mass and radius...

Hello, everyone. On physics Olympiad in our country I get a interesting example... But, I didn't know how to solve it. Can you tell me how? It is known that the Moon when it is full has the apparent magnitude of approximately -12 mag and the Sun during the day has the apparent magnitude of...

I've never understood why changing the albedo of an object will change the temperature of the object. As I understand it the albedo is a factor that determines the amount of light reflected off the surface. This means that a low albedo will mean that more light-energy is absorbed. Thermal...

Hi, I am studying thermal radiation. Does anyone know what is a connection between emissivity and albedo. Regards, Mike

If our sun is the source of illumination, how can an object be observed from the Earth at full phase? Wouldn't the Earth eclipse the object? So then why can we see a full moon during full phase? Is it because the moon's orbit is inclined wrt to the Earth-Sun orbit? If so then wouldn't this by...

1. This question isn't so much a homework question per se, however I am having difficulty using certain equations to find the albedo of the Earth. In attempting to find the albedo, I am using two equations, shown below, however each equation gives a different answer. I am given the following...

Homework Statement If the Earth's average cloud cover increased, what effect would it have on the albedo temperature? If the Earths albedo increased to 0.32, what would be the average temperature? Ok I thought that if the albedo was higher, it would reflect more light, thus coolign would...

Hi, Im doing an IB Extended essay on astrophysics, on the planning stage. My aim is to calculate the surface temperature of an extrasolar planet. I have most of the caculations done, but I am stuck on just one part - calculating the Bond albedo of the planet. I know what the geometric albedo...

https://www.physicsforums.com/showthread.php?t=245558 The attached table shows polar satellite (MSU) atmospheric temperature patterns posted on UAH covering 29.5 years. Note the LT contrast between the north polar and south polar regions, a 1.3 oC rise vs. a 0.2 oC loss. While the northern...

The Danish scientist Henrik Svensmark has been scorn for several years now because of his alternative explanation of how Earth's temperature varies. His theory states this: High solar activity is a sign of a strong magnetic field from the sun -> Strong magnetic field from the sun will decrease...

Hi all, I'm looking for a way to calculate how much light is reflected from the surface, on the moon, and whether that light would be strong enough to be classed as a bright light source. I have no idea where to start with this, but basically I'm trying to prove a Lunar Hoax Conspiracy...

Suppose I was to publish this study. **** Andre et al, 2006, Earth Albedo variations dwarf greenhouse effect EOS, Vol. 87, No. 4, 24 January 2006 Abstract We compute Earth albedo (reflectivity) in the period 1984-2004, using cloud data and coverage, confirmed by measuring reflectivity of...