Another asteroid whizzes past Earth hours after discovery
earthsky.org
earthsky.org
Every time I point this out there's always someone who pipes in "earth based astronomy is dead". I'll head that off at the pass right here because that's incorrect.
So we have space based telescopes. They are very expensive, and the logistics of what they can look at, when they can look at it, and when they can communicate with the ground complicate their operation.
Also they have better things to look at. Why build the most powerful and expensive telescope just to point it at the moon which you can see with a $200 telescope from Wal Mart?
Earth based astronomy is still a primary source for information. Why limit yourself to half a dozen space based assets when you have countless more on the ground? Save the space based assets for their intended purpose and use earth based assets for nearby objects.
When I worked on the Chandra team one of the problems they face is the condition of the shielding on the craft is deteriorating. So even if there were something super interesting to look at, the craft might not be able to look at it if it would be exposed to radiation for too long.
Edit: sources
[1] https://www.sciencealert.com/the-international-astronomical-...
[2] https://gizmodo.com/astronomers-rally-to-stop-starlink-and-o...
[3] https://iopscience.iop.org/article/10.3847/2041-8213/ac470a
[4] https://www.quora.com/Why-cant-astronomers-use-software-to-r...
"The streaks are most apparent in so-called twilight observations, those taken at dawn or dusk, which are important for finding near-Earth asteroids that appear close to the sun in the sky. ZTF has discovered several asteroids of this nature, including 2020 AV2, the first asteroid spotted with an orbit that fits entirely within the orbit of Venus.
"In 2019, 0.5 percent of twilight images were affected, and now almost 20 percent are affected," says Przemek Mróz, study lead author and a former Caltech postdoctoral scholar who is now at the University of Warsaw in Poland."
We may potentially have a serious problem on our hands unless we really ramp up exterrestrial observation, or maybe we won't have a problem, we might just all be dead on impact.
Link to article https://www.caltech.edu/about/news/palomar-survey-instrument...
“Yet despite the increase in image streaks, the new report notes that ZTF science operations have not been strongly affected. Study co-author Tom Prince, the Ira S. Bowen Professor of Physics, Emeritus, at Caltech, says the paper shows a single streak affects less than one-tenth of a percent of the pixels in a ZTF image.
"There is a small chance that we would miss an asteroid or another event hidden behind a satellite streak, but compared to the impact of weather, such as a cloudy sky, these are rather small effects for ZTF."
If the effects are small compared to cloudy weather, is it really that serious of a problem?
What happens when every developed nation wants to launch their own constellations?
It’s kinda the same situation as environmental pollution. Is the world justified in restricting a developing nation from undergoing their industrial revolution like others have before simply because they were too late to the party?
What kind of wars is this going to cause?
The asteroids in question are tiny. One of the links in the article under discussion is to a previous article about an asteroid that hit the Earth near Iceland 5 hours after being detected. It was about 3 meters wide. That's way too small to justify worries about global damage on impact.
Then it's a lot easier to see, and we would see it a lot further away. The seeing difficulty issues people are talking about in this thread don't apply to asteroids that large.
This won't happen for an asteroid large enough to be a threat. Those asteroids are easy enough to see that the Starlink constellation does not impede their detection. That was the point of my previous post (the GP of yours).
(Granted it's multiplying small probabilities, but so is this whole discussion, so I don't feel too bad about it.)
Yes. The key point is that the larger the object, the further away we can see it. And the further away we can see it, the more time we have between the initial sighting and any possible collision with Earth.
The lower bound for a "potentially hazardous object", i.e., one that could cause disastrous damage in a collision, is 140 meters wide, and we can see those far enough away that they are years to decades from getting close to Earth (i.e, time enough to plan a space mission to deflect them enough to miss Earth). Newer surveys are getting to the point where they can detect 10 meter wide objects, which can still cause substantial damage (similar to, say, a hurricane or a tornado), far enough away that they are days to weeks from getting close to Earth (i.e., more than enough time to evacuate possible impact areas if needed).
Even if such an object were temporarily occluded by a low Earth orbit satellite, the occlusion would only last for minutes at most (because the satellite and the distant object are moving across the sky at very different rates). So for objects of the above sizes, occlusion doesn't prevent us from seeing them well in advance.
See here for more info:
Larger asteroids are much easier to see, and the issues being discussed with difficulties in seeing in this thread don't apply to larger asteroids.
There's even other objects in the sky/space that aren't man-made that also move, and most of them we know about as well.
If there's a click bait title that is going to drive views they'll print.
You might be right. I doubt that. These don't strengthen your position
Did you read the sources linked to?
do you have other information?
[1] https://www.sciencealert.com/the-international-astronomical-...
[2] https://gizmodo.com/astronomers-rally-to-stop-starlink-and-o...
[3] https://iopscience.iop.org/article/10.3847/2041-8213/ac470a
[4] https://www.quora.com/Why-cant-astronomers-use-software-to-r...
Ask if we should end funding for a ground based observatory and you will hear a very different story: ~“Starlink blocks up to 0.1% data collected by ground based telescopes, that isn’t inherently a big deal.”
The truth is someone in between, a few kinds of observations are being significantly impacted while most are largely able to avoid the issue.
Some data will always be lost, as the satellites do obstruct part of the night sky, However the fractional area obstructed is exceedingly low.
That is to say, If you dump pixels with satellites, you will have fewer pixels. However, the number of pixels is low and changes with time.
(I know nothing about this.)
Also StarLink is not for everyone, just for (globally speaking) rich people.
I think the website cites urban but it's not really specific to that.
From https://terragraph.com/product/
I don't think this is a solution for remote areas.
supposedly it was developed for remote areas. Hard to tell if there's something special about where it was deployed....maybe the notion of remote has to be still close to wired basestation hubs.
The amount of launch capacity we now have, and the massive drop in cost per tonne to orbit, means spaceborn telescopes are cheap now, with the added benefit of no atmosphere.
And as costs to launch have dropped, so can costs to build. We don't need to spend loads of cash, since the cost of launch is so cheap, we can just throw a replacement up if it goes bust.
In fact, we don't even need telescopes to scan our neighborhood... just loads of smaller video capturing cameras, with excellent zoom lenses. If 10% fail, who cares?
It's time to think about proper near earth detection, not the pot luck stuff we've been doing so far.
And it's time to think in terms of the launch capacity we have..
We have far better tools at our disposal and with a full mesh network of satellites providing optics, we could have an amazing early detection system with total spatial coverage.
This is the alarmist pop-sci all the sources are known for pumping out
Can we build a new generation of space based asteroid observers? I know that this is a reactive approach but I don't see those constellations coming down. We could prevent expansion but they are damned helpful. In the past space telescopes were a big affair to launch one system. But what if we launched a constellation of 100 or 500 space based telescopes? Is there a way to move forward to solve this? Or what is the solution?
Those arguing that LEO internet satellites are an existential threat had better come up with a rural internet alternative if that’s their position. Because internet availability is a genie that’s not going back in the bottle.
This is coming from someone who lives in a rural area without reasonable internet options and is on the Starlink waiting list. I’d rather be alive than have lower-latency connections to Reddit.
Yeah, my understanding was that this size of asteroid was nearly impossible to detect under even ideal conditions, anyway.
Click bait?