These are unsolved either because not enough information is available to evaluate, or no solution presents itself from available information. Just because a sighting is unsolved does not indicate that it is an alien space ship. Any of these could be fabrications, but there is nothing to indicate that any of them are.

A "C" followed by a number refers to the Colorado University study case numbers

Updated 02/22/14

Date/timeLocationWitnesses ID Description - (KEY)SourceID-er
04/L6/1917 dyTTFatima Portugal(many) Lights and disc, Virgin Mary appearance=JV
**/**/46 ntTT(various) Sweden(many) Ghost rockets flew over Sweden horizontally, some fell into lakes.ERRU
12/L2/48 ntTT(various) NM(many) Green fireballs appeared near military basesERRU
Date/timeLocationWitnesses ID Description - (KEY)SourceID-er
04/27/50 ntTTSouth Bend INair: Manning+Adickes+ Red round UFO paced plane for miles, dove when plane turned toward it, was below horizon at times =T67
05/29/50 ntTTMt Vernon VAair:Willis Sperry Bluish fluorescent light, appeared as finless submarine shape when silhouetted on moon, circled plane ERRU
11/**/51 ntTT(various) NM(many) More green fireballs near military basesERRU
Date/timeLocationWitnesses ID Description - (KEY)SourceID-er
05/01/52 dyTTTucson AZ(many air) Small disc flew in B-36 prop wash, another one flew pastERRU
07/14/52 ntTTNewport News VAair:Nash, Fortenberry 6 red circles came toward plane from front, passed underneath it; objects reversed course and sped away in front of the plane, joined by 2 more =T67
07/29/52 TTTTPort Huron MI(many, air) Object outdistanced F-94; air visual, 1 air and 2 ground \/ sets ERRU
10/04/54 TTTTPoncey FranceFourneret+ Luminous body, $F$ hole in ground, earth removed and scattered, but roots undisturbed =JV
Date/timeLocationWitnesses ID Description - (KEY)SourceID-er
04/14/57 dyTTVins-Sur-Caramy FranceGarcin, Rami +3 Top-shaped object landed, hopped over 2 metal signs, which vibrated when object came near. =JH
11/04/57 TTTTOrogrande NMStokes Cigar object near road, auto engine and radio failedERRU
02/24/59 TTTTOrogrande NM(?) Speedometer read up to 110 mi/hr while UFO present

02/24/59 ntTTPhilipsburg PA to Cleveland OH(air: Peter Killian) 3 white discs moved in changing formation as they paced plane, seen from other planes =DK
Date/timeLocationWitnesses ID Description - (KEY)SourceID-er
01/10/61 TTTTCape Canaveral FL(mil) Radar tracking lost Polaris missile by locking onto a UFO instead=DK =FE
07/07/61 ntTTBeulah MI(many $Y%) Blue-white object fell to earth, red glow appeared behind trees with rotating beacon effect, small red and white objects approached witnesses, who sped off in car. Possible unrelated lights. =S67
07/20/61 dyTTBeaumont TX(air Beatherd, Cazzell) Bright UFO seen by pilots =S67
08/07/63 2045Fairfield ILHill, Uphoff Hovering kite shaped object upset dogs, changed from orange to gray to blue-white, 25 minute duration =N=
05/03/64 TTTTCanberra Australia(many) Large white glow wobbled up to small red one, struck it, flew away without wobbling, red one faded out

Date/timeLocationWitnesses ID Description - (KEY)SourceID-er
02/02/66 ntTTEvanston IL(A) Diamond shape with orbiting balls, constantly changing color, moved slowly across sky =S67
NN/NN/69 ntTTWaikiki Beach HI($Y$ A+) Multicolored glowing objects milled around in a swarm seen out to sea; swarm slowly drifted across night sky, always at low elevation =LR
02/14/74 ntTTEly NV(A) 5 cyan UFOs approached a truck, it broke down, the drive shaft turned when truck was stopped in neutral (The truck problem has since been explained by the driver shifting with the "handier" axle ratio selector instead of the gearshift, damaging the unsynchronized differential, but the UFOs are still unexplained)

Date/timeLocationWitnesses ID Description - (KEY)SourceID-er