A Mass of UFO sightings has Territorians wondering if we are on the brink of an alien invasion.

There have been seven separate Top End UFO sightings reported in the past week. Hardly a night has passed without a sighting of some "unexplained phenomena" since the first sighting last week.

Almost all of the sightings have been in Darwin's rural area.

The first sighting was reported by a woman who wanted to be identified only as Shirel on April 21.

She said she saw the strange lights from her Humpty Doo home hovering over Howard Springs.

"The lights were really low in the sky, really bright, with flashing dots," she said.

"Three of them formed a semi-circle and they hovered over the area for at least half an hour."

There were three separate sightings on Friday night including British backpacker Kylie Myers who said she had "never believed in anything like UFOs" before her strange encounter.

The 27-year-old tourist said she turned into a "believer".

Ms Myers said she stopped her car on the side of the road to grab her camera from the glovebox, but the light disappeared.

"It was pretty spooky."

There were more sightings at Coolalinga on Saturday, Acacia Hills on Sunday and again in Howard Springs on Tuesday.

But astronomer Geoff Carr yesterday told the Northern Territory News he was "far from believing any of this UFO stuff".

"Unless aliens have found a way to travel faster than light speed, it's a doubtful thing to believe they came to visit us," he said.

Mr Carr said he believed 99.9 per cent of all the UFO sightings could be explained as simple weather phenomena.

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The following UFO sightings have been reported to the NT News in the past week.

April 21, night-time, Humpty Doo/Howard Springs

Thirty eight-year-old Shirel and her family see "strange lights" from their Humpty Doo home. The lights seem to hover over Howard Springs.

"The lights were really low in the sky, really bright, with flashing dots.

"Three of them formed a semi-circle and they hovered over the area for at least half an hour."

April 23, 8pm, Howard Springs

Susan Clarke and her family spot a "huge spherical object that was moving horizontally across the night sky very slowly".

"It was amazing and unnerving at the same time.

"It was glowing red, orange and gold - none of us had ever seen anything like it before."

A 48-year-old woman of Woodroffe later confirms the sighting and compares it to a similar UFO sighting in Howard Springs in September last year.

"It was sitting there, maybe 40 metres above the house - I first thought it was a huge full moon.

"When I looked around I saw that there was a partial moon further to the left, and I thought 'Oh my God, I'm not hanging around here' and took off.

"It was unnerving, it was a dark, very quiet night, and really, it scared me to bits.

"It was an enormous orb, just sitting there, as if it was waiting for something."

April 23, night-time, Stuart Highway, south of Howard Springs

British backpacker Kylie Myers is on the way to Adelaide River, when she suddenly sees "this big light" in front of her, a few metres above the road.

"It slowly moved to the right, then to the left ... and then it slowly flew to the left.

"A second later somebody must have switched the light off - it was gone as suddenly as it appeared.

"I never believed in anything like that, I always thought people would make it all up or see strange things when they are drunk, but this really happened to me - and it was pretty spooky."

April 24, 10pm, Coolalinga

Twenty seven-year-old Renee Miller sees a huge yellow light over the road.

"It was just there, it wasn't the moon or anything.

"It was bright yellow - and suddenly it was gone. I have no idea what it was."

April 25, 8pm, Acacia Hills

UFO-spotter Alan Ferguson sees a "bright white light" flashing past his house. "It just looked like the International Space Station - a big white light," he said.

"When it moves across it looks like a satellite, except it's huge.

"It's exactly the same thing that I saw at this time last year."

April 27, 10.30pm, Humpty Doo/Howard Springs

Humpty Doo-resident Shirel again spots mysterious lights over Howard Springs, together with her husband and her two grown-up children.

"We saw the same thing again - there were three of them (bright lights) in a semi-circle.

"It was a crystal clear night and we all saw it. We watched it for half an hour and the things changed their shape a few times.

"It looked like a long piece with lights on the side, but every now and again it just looked like a star.

"We weren't worried as it was too far away, but it's a bit of a worry to hear more and more people report strange things happening."