It's World UFO Day. What's that in the sky? Subway delivering by drone in 2 Florida cities

Today is World UFO Day.

And if that isn't enough to get you looking up ...

Subway will start delivering its new Footlong Dippers for a limited time in five cities across the U.S., including two in Florida.

It's not just for everyone, though. Here's what you should know.

What is World UFO Day?

"World UFO Day commemorates two separate dates: June 24 and July 2," according to National Day Calendar.

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"The June 24 date recognizes the first widely reported UFO sighting in 1947 by aviator Kenneth Arnold. The July 2 date commemorates the incident that took place the same year in Roswell, New Mexico."

Private pilot Kenneth A. Arnold said he saw nine shiny circular objects while flying past Mount Rainier on June 24, 1947, according to National Air and Space Museum. He calculated their speed at about 1,200 mph.

Media accounts at the time turned what Arnold saw into "flying saucers," a term that's been used since for unexplainable aerial phenomena.

The same year, rancher W. W. “Mac” Brazel found something odd on his property in New Mexico, and so the Roswell incident began, which entangled the U.S. Army in UFO conspiracy theories that persist to this day, according to National Air and Space Museum. The Army said what Brazel found was a high-altitude weather balloon.

Have any UFOs been spotted in Florida?

There have been plenty of UFO reports from Florida and you don't have to go back very far to find the most recent reports, according to the  The National UFO Reporting Center.

➤ Interactive map: See reported events in Florida, US and around the world

We're talking last week.

• On June 20, "unexplainable lights" were reported from Key West.
• On June 19, a "black triangle, very low, no noise" was reported from Jacksonville.
• And on June 12, a "luminous craft" was seen over downtown Orlando.

Today, June 24, another sort of "craft" will be seen over Orlando.

Orlando, Miami, Florida to see Subway drone deliveries

On June 24, Subway drones will deliver the Ultimate Footlong Offering — UFO, get it? — Subway's all-new Footlong Dippers, the Footlong Cookies and the iconic Footlong Sub in five U.S. cities:

• Miami
• Orlando
• Denver
• Dallas
• Atlanta

The drone deliveries will celebrate the Ultimate Footlong Offering available nationwide, according to a Subway news release.

Even drones, though, are subject to Florida weather, and Subway noted "drone delivery is subject to change due to weather or other atmospheric conditions."

Subway offering 20% off any footlong sub

If you don't live in one of the cities where drones will be available for delivery, you can still see something else worthwhile: a 20% deal.

The Ultimate Footlong Offering will be available from June 24 through July 1. Get 20% off any footlong sub when ordered with a Footlong Dipper and Footlong Cookie.

Get the deal by using promo code UFODAY when placing your order either on the Subway app or Subway.com.

Will Subway drone deliveries be available to everyone in those cities?

No. The drone deliveries will be available to the most active MVP rewards members.

What's a Subway Footlong Dipper?

The Footlong Dipper is one of the newest additions to Subway's menu.

Available for $3 on Subway's Sidekicks menu nationwide, the Footlong Dipper was described as the "perfect swirl of cheese and meat, tightly rolled in Subway’s soft and bubbly lavash-style bread." It also comes with a choice of one of Subway’s 11 signature sauces, offering 33 different flavor combinations.

It's available in three varieties:

• Pepperoni and cheese
• Chicken and cheese
• Double cheese

Yes, Subway's Footlong Cookie has returned to earth

Subway's Footlong Cookie returned to Subway's Sidekick menu after months of demand from customers.

The company announced in May the cookie was returning to restaurants nationwide and would be available for $5. Prices may vary by location.

"Packed with gooey chocolate chips, the Footlong Cookie is a "much-needed morale booster," Subway said in a news release.

"The Footlong Cookie has delighted millions of Americans since their first bites in January, sparking unprecedented demand over the last several months," said Paul Fabre, senior vice president of culinary and innovation at Subway.

"Subway worked diligently to rush additional Footlong Cookie supply to satisfy cookie cravings at a great value and serve up a footlong dose of happiness this summer."

Trivia: Hynek Scale measures UFO sightings

After the two incidents in 1947, the Air Force launched an investigation called Project Sign, calling for expert advice from an astronomer to sift through all the reports being sent in from the public.

The astronomer chosen was J. Allen Hynek at  Ohio State University, 60 miles from Wright-Patterson Air Force Base.

According to History.com, over the next year, Hynek's team reviewed 237 cases. In his final report, he noted that:

• 32 percent of incidents could be attributed to astronomical phenomena
• 35 percent had other explanations, such as balloons, rockets, flares or birds.
• 13 percent didn’t offer enough evidence to yield an explanation.
• 20 percent that provided investigators with some evidence but still couldn’t be explained and were classified as "unidentified."

In his 1972 book, "The UFO Experience: A Scientific Enquiry," Hynek devised a sixfold classification for UFO sightings, according to Enigma Labs:

• "Nocturnal Lights: Lights in the night sky.
• "Daylight Discs: UFOs seen in the daytime, generally having discoidal or oval shapes.
• "Radar-Visual: UFO reports that have radar confirmation—these supposedly try to offer harder evidence that the objects are real, although radar propagation can be occasionally discredited due to atmospheric propagation anomalies.
• "Close Encounters of the First Kind: Visual sightings of an unidentified flying object, seemingly less than 500 feet away, that show an appreciable angular extension and considerable detail.
• "Close Encounters of the Second Kind: A UFO event in which a physical effect is alleged; this can be interference in the functioning of a vehicle or electronic device, animals reacting, a physiological effect such as paralysis or heat and discomfort in the witness, or some physical trace like impressions in the ground, scorched or otherwise affected vegetation, or a chemical trace.
• "Close Encounters of the Third Kind: UFO encounters in which an animated entity is present — these include humanoids, robots, and humans who seem to be occupants or pilots of a UFO."