In these screenshots I took from Google Maps you can see they seem to open and close. I’ve seen conspiracy theory types claim they are secret tunnel entrances. I don’t believe that but they are odd.
They are Southwest of Area 51 in an area with tons of bomb craters:
Deep bomb craters with shadows based on sun angle. Inside "Area 51"
It would’ve been more useful to give us a link to Google maps so we could tell exactly where those are. The general area southwest of Area 51 is the former Nevada Test site, where nuclear weapons were tested. Those look like the subsidence craters that are common there.
Here’s a link to a Google map showing the main test crater field with hundreds of them:
As to the dark & light portions within a particular crater, that’s simply the shadow of the rim partly covering the crater.
Note that since the Google overhead pictures are taken at different times by airplanes that are flying and hence moving while they shoot, the fact the shadows on two craters don’t exactly align is not evidence of fakery. In fact it’s evidence of reality.
Late edit: I couldn’t embed the atellite view. Just click the image postage stamp at lower left to switch to the pictures and the craters will be obvious.
A hair north of the view you posted is the 400 yard across crater from the Sedan shot. Big crater. Which you can take tours to see, COVID-permitting. Though only during times that it’s not being used by the really big flying saucers…
The excavation test moved 12 million tons of earth with a 104 kt yield device, per the wiki. Also per the wiki, it exposed 13 million US residents to radiation.
Haven’t you all seen Tremors?
Magazine!
Here!
One of my favorite schlock movies!
Q: Why do you have cannon fuze?
A: For my cannon, of course.
I am much more concerned with whats here -
“clearly” that is an alien infant.
Mole people
@simster: Yeah, we’re gonna need a bigger can of Raid for that one.
Those craters bear an uncanny resemblance to the sand pit from Invaders From Mars.
It’s a documentary.
It’s not so “former.” I go there on occasion. But, you’ve hit the nail on the head–they’re the leftover craters from “shots” of long, long ago.
Tripler
I can neither confirm nor deny they are underground lab testing of Klingon disruptor technology.
Good catch. I didn’t say that very well. And I muffed the capitalization.
I meant it’s the test site formerly known as the “Nevada Test Site”. And it’s the place where nukes had formerly been set off forming the craters the OP was worried about.
Open sources say “interesting” stuff up your alley still happens there now and again, but probably not the really large crater-forming kinds of “interesting”.
We’d quit doing “shots” starting with the 1991 Moratorium. There’s still a lot of “interesting stuff” that happens out there. One of the cooler things to do when “stuff” is done and finished, is to go check out Sedan Crater.. Yes, it’s a big hole in the ground, but I find it more intriguing than Meteor Crater.
Tripler
Sedan’s less ‘touristy,’ if you know what I mean.
They are worm hole termini that open and close when aliens arrive or leave Area 51. Area 51 is actually a Men in Black type headquarters and is thus very busy.
@Tripler: I flew out of Nellis for 4 years, basically the late 80s. Spent a lot of time in the R airspace surrounding NTS & Area 51 on all sides. Sometimes when the air is clear and the lighting is right you see some cool stuff.
Unfortunately, your operative word “flew” indicates past-tense. I was gonna wave at ya next time I’m out there. Every fly over the UTTR? That’s another area I am intimately familiar with.
Tripler
UTTR = Utah Test and Training Range. Get yer mind out of the gutters, you perverts. 
I will add that sometimes those craters creep up on you! You might think that doing 55 on a 35 mile an hour road will save you some time, but not when you have to slam on the brakes because the road sharply curves to the right or left. Those damned “giant potholes” would be a minor headache.
Tripler
“Hi, Hertz roadside assistance? I need a tow truck–I hit a crater.”
The REAL reason for those holes-
We failed to turn left at Alberquerque!
