No. Here’s why. The “watchers” are found in Daniel, in the English Standard Bible and Darby translations only. This is more a translation preference than a theological revelation.

“I saw in the visions of my head as I lay in bed, and behold, a watcher, a holy one, came down from heaven...” Daniel 4:13

“The sentence is by the decree of the watchers, the decision by the word of the holy ones, to the end that the living may know that the Most High rules the kingdom of men and gives it to whom he will and sets over it the lowliest of men.’ Daniel 4:17

“And because the king saw a watcher, a holy one, coming down from heaven and saying, ‘Chop down the tree and destroy it, but leave the stump of its roots in the earth, bound with a band of iron and bronze, in the tender grass of the field, and let him be wet with the dew of heaven, and let his portion be with the beasts of the field, till seven periods of time pass over him,’ Daniel 4:23

Other translations use the word “messenger,” a term frequently applied to angels. So the term “watcher” is unique to only certain translations.

The word “watcher” shows up in one other place. Job 7:20, where Job directly calls God a “watcher of mankind.”

People will try to make the same connection between the Bible and UFOs from the book of Ezekiel. Just check out chapter 1:

I looked, and I saw a windstorm coming out of the north—an immense cloud with flashing lightning and surrounded by brilliant light. The center of the fire looked like glowing metal, and in the fire was what looked like four living creatures. In appearance their form was that of a man, but each of them had four faces and four wings. Verses 4-6

As I looked at the living creatures, I saw a wheel on the ground beside each creature with its four faces. This was the appearance and structure of the wheels: They sparkled like chrysolite, and all four looked alike. Each appeared to be made like a wheel intersecting a wheel. As they moved, they would go in any one of the four directions the creatures faced; the wheels did not turn about as the creatures went. Their rims were high and awesome, and all four rims were full of eyes all around. Verses 15-18

These strange visions are attempts by people to explain the appearance of angels, who are “aliens” in their own way. They are spiritual beings, appearing in our natural world, reflecting the brilliance and holiness of God. But the imagery all has meaning. For example, the wheels and eyes represent God’s all-seeing omniscience...not a round spinning space ship from Mars.

It’s important to note that both Ezekiel and Daniel call these “visions,” not moments in reality. They didn’t see these things with their own eyes, but with their spiritual eyes. Revelation has similar descriptions of angels during John’s vision. This can’t prove the existence of space aliens if it’s a dream.

We know they are angels because the messages they leave have to do with God and his plans for the future. Why would God send space aliens when he has angels who act as messengers all the time?

Every time someone suspects an alien conspiracy, it usually happens in books like Daniel, Ezekiel or Revelation. Why? Because these are apocalyptic books that use strange images to describe mysterious visions with confusing messages. People try to interpret those passages with their own meaning. No passage in the Bible shows Moses on the mountain with a huge spaceship over his head or Jesus ascending into heaven with a particle beam. We can’t apply meaning to Bible passages whose meanings are sometimes unclear or strange.