3 small balls of light coming from different directions dissapeared into a dark spot in the sky. They were not satellites.While going for a walk on Wheeler dam off of north main street in Salem. My friend and I were looking at the stars when we stay 2 balls of light just above the atmosphere flying from the direction of Arlington pond. At first I thought the balls of light could have been a couple satellites. Which is very common to see at night when star gazing. Both object disappeared once they reached a certain point in the sky. Suddenly as both balls of light disappeared we noticed a 3rd light approaching from the Haverhill Ma direction. This ball of light disappeared when it reached the same location in the sky. All the objects reached the same point in the sky within about 10-15 seconds of each other. As we stood in disbelief we noticed that the point in the sky where the objects disappeared seemed to black out other stars. We noticed a circler type black spot in the sky. Then we noticed the dark spot slowly fade out revealing the stars behind it. After the whole incident ended we noticed a very unusually amount of small engine aircraft in the area. Just small planes, No helicopters. We counted 5 planes total. Which is also unusual for this particular area. (3) balls of light and (1) dark circle in the sky that blocked out stars. for a total of what I would consider to be (4) objects.