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69 votes

Why does it take so long to transmit an image from New Horizons to Earth?

New Horizons has just passed the Kuiper Belt Object (KBO) 2014 MU69 also known as Ultima Thule. KBOs form a belt of asteroids (the Kuiper Belt) from Neptune's orbit outwards and of which Pluto is the ...
astrosnapper's user avatar
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47 votes

Why does it take so long to transmit an image from New Horizons to Earth?

The other answer mentions it, but this gives a bit more theory as to the why. It's effectively for the same reason that your phone or Wi-Fi don't work as well and slow down when that they are far ...
The_Sympathizer's user avatar
26 votes

How did asteroid (7482) 1994 PC1 get its "face"? Is it reconstructed from optical or radar imaging, or something else?

These are images taken from Nasa's Eyes on Asteroids site. It lets you see the orbit and get information about the asteroid in a nice interactive way. For asteroids with a known shape and surface ...
James K's user avatar
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22 votes
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What is the most common activity of astronomers in the JWST?

JWST operates in a mode where groups of astonomers make detailed proposals to observe particular obects with particular instruments. There are no random pointings, although there may well be ...
ProfRob's user avatar
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20 votes
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What is sin i in this graph and why is it there?

If you discover an exoplanet via the Doppler (radial velocity) method, then the amplitude of the radial velocity variations depends on the inclination, $i,$ of the exoplanet's orbital axis with ...
ProfRob's user avatar
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17 votes
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How do you propagate asymmetric errors? (on the practical way to...)

I'm not sure this question really belongs here, but you mention the word "astronomy", and I'm an astronomer and I have an opinion on how to add numbers with asymmetric uncertainties: ...
pela's user avatar
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16 votes

Why does it take so long to transmit an image from New Horizons to Earth?

On top of the slow data transmission rate (explained in astrosnapper's answer), I think it is worth pointing out that New Horizons will enter solar conjunction next week, meaning that we won't be able ...
walen's user avatar
  • 286
15 votes

Why does it take so long to transmit an image from New Horizons to Earth?

Just to put some perspective on things: 1. New Horizons is really far away from the Earth. At the moment of closest approach, New Horizons was over 6,600,000,000 kilometers away from Earth. This is ...
ahiijny's user avatar
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14 votes
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On what basis is the information about the distance and velocity of the Voyager probes determined?

On what basis is the information about the distance and velocity of the Voyager probes determined? For distance: round-trip travel time of radio signals For velocity: Doppler-shift of round-trip ...
uhoh's user avatar
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13 votes
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Role of power laws in astronomy?

Scale invariance and self-similarity Power laws basically mean that there is no preferred scale, i.e. that a physical property is scale invariant. Any deviation from a power law means that the ...
pela's user avatar
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11 votes
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Why do we use FITS format for scientific images especially in astronomy? How is it different from formats such as JPEG, PNG etc?

File formats tend to be industry/field-specific, with the format, tools, and expectations of the field coevolving to become more dependent on each other over time. JPEG co-evolved with amateur digital ...
Larry Gritz's user avatar
11 votes
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Will there be public access to the New Horizons data from Ultima Thule?

The raw images1 from LORRI (high resolution greyscale) are available from JHU APL but the rest of the data such MVIC (wide angle in greyscale plus four color bands: near IR, methane, red, and blue), ...
Alex Hajnal's user avatar
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11 votes
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Is there any site with telescopes data?

Most general purpose observatories release the data taken on their facilities after the expiration of the proprietary period (this is the time, typically 12-18 months, where the data is only available ...
astrosnapper's user avatar
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11 votes
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Locate stars in sky from list of (x, y) co-ordinates

Upload your photo to nova.astrometry.net and in a few minutes you will get a result page that tells you the plate scale in arcseconds/pixel, the celestial coordinates of the center of the frame, the ...
amateurAstro's user avatar
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11 votes
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Could an hypothetical hidden black hole companion to the sun be revealed by proper motion data?

A black hole at a distance of 10,000 AU (comparable to the separation of Proxima from Alpha Centauri) could mean that the sun was in an orbit lasting longer than 200,000 years. So in two hundred years,...
James K's user avatar
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10 votes
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Questions about convolving/deconvolving with a PSF

Convolution is not a uniquely invertible process in the presence of random noise in your image. Deconvolving a noisy image can give misleading results, even if you have perfect knowledge of the PSF. ...
ProfRob's user avatar
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10 votes
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What is the "lost light" in this unusual Hubble Deep Sky image?

Let me see if I can explain the main aim and accomplishment of this work. First off: the picture you're puzzling over is a "luminance RGB" image, in which the bright regions are represented by color (...
Peter Erwin's user avatar
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10 votes

How has the resolution of astronomical spectrographs improved over time?

There are probably two aspects to this. First, is there a progression in the technological capability to produce spectrographs that are of higher and higher resolution - almost certainly. Second, is ...
ProfRob's user avatar
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9 votes
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Milky Way position on the sky

There is a very nice project called d3-celestial by Olaf Frohn on github. In contains a data file describing the Milky Way as polygons, see here. A demo showing this Milky Way can be found here. And ...
mtewes's user avatar
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9 votes
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If I can't unscramble an egg, how do Astronomers unscramble views gravitationally lensed by complex mass distributions?

I work in gravitational lensing, so maybe I can give you an idea. In those JWST you have a massive galaxy cluster that is bending the light behind and acting as a true lens. If you have a temptative ...
JOAQUÍN HERNÁNDEZ's user avatar
9 votes

What is the most common activity of astronomers in the JWST?

No, not randomly, see Is pointing a telescope at a random place a viable astronomical strategy? The closest thing to "pointing randomly and seeing what is there" would be "deep field&...
James K's user avatar
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9 votes

What is the most common activity of astronomers in the JWST?

Generally, the observation time is scarce, the pointing of the telescopes is very accurate over extended periods of time; e.g. the pointing accuracy and stability of the JWST are given as "The ...
planetmaker's user avatar
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8 votes

What is the "lost light" in this unusual Hubble Deep Sky image?

When you plug the lead researcher's name into Arxiv, the first search result is The missing light of the Hubble Ultra Deep Field. 3 main steps: Creation of sky flat fields for the four filters....
Hobbes's user avatar
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8 votes
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Is there a database of all known star names/identifiers?

The closest service to what you are describing is the SIMBAD Astronomical Database from the Université de Strasbourg/CNRS. At the time I write this post, it contains 10.8M objects and 35.5M ...
Demitri's user avatar
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8 votes
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Is looking through a telescope to do astronomy a thing of the past?

Scientifically there's little to gain when you look through a telescope with your own eyes. Attach a camera to the telescope and you immediately document what you observe and take out the subjective ...
planetmaker's user avatar
  • 19.9k
8 votes

Role of power laws in astronomy?

I have to admit that power-laws (in general) used to be my shtick so I am happy to shed some light on their general importance in physics which obviously also hold for astronomy. The main idea of a ...
B--rian's user avatar
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8 votes
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What is z in this program?

Welcome to the world of software developed by scientists for their own use. There are not many clues. The top-level README cites Nemravov√° et al. 2016. That paper mentions PYTERPOL briefly in section ...
Mike G's user avatar
  • 18.7k
8 votes

What's a good example of published astronomy pipeline coding libraries

I think one really nice example right now is the James Webb pipeline. I haven't dived into the internals yet but I think it does a good job of demonstrating the best-practices of software engineering ...
Roy Smart's user avatar
  • 1,632
7 votes

Are there any astronomical phenomena that could emit strong radio waves with multiples of a discrete frequency?

I think you've misunderstood the article - the quantity that seemed to be occurring at integer multiples of some number isn't the frequency of the radio emission but rather the dispersion measure (DM) ...
HDE 226868's user avatar
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