The stars that are visible in the local sky on any clear night of the year, at any time of the night, are called Circumpolar stars.
A circumpolar star is a star that is close to one of the celestial poles and never sets below the horizon hence they are visible from one location throughout the year and one can even see them in the daytime if the sun does not glare.
• sum of squared differences
Ψ(f1, f2) = −∑|f1(ri)− f2(ri)|2
• correlation
i
Ψ(f ,f )=∑
Answer:
B. local water contamination
D. destruction of ecosystems
Explanation:
The mining, be it a surface one or underground one, has several negative impacts on the surrounding area. Two common negative impacts of both types of mining are contamination of the local waters, as well as the destruction of ecosystems.
The waters get heavily polluted with toxic chemicals pretty much always ad everywhere where there is mining. The main reason for this is that the nus-products from the mining are released into the waters. This causes high level pollution of the waters, thus making it not good for anything, and the aquatic life in the waters dies out rapidly.
The fact that the waters are heavily polluted means that everything that comes in touch with them becomes heavily polluted as well. Also, apart from releasing chemicals in the waters, the mining requires space, so the area is cleared out, and after that lot of toxic material is disposed on it. The majority of the plants can sustain that, so they die out, and since they are the basis of the ecosystems, the animals die out as well.
