As you can see, a real line up hardly ever happens.
Besides that, this line up was a line up with the Sun, too; it would occur at Jupiter full phase. Mr. Hooker, the chief meteorologist, announced that it had been calculated that such a perfect line up would not occur again for more than two hundred thousand years. You can bet we were all waiting to see it. The Project Jove scientists were excited about it, too, and special arrangements had been made to observe it.
Having it occur at Jupiter full phase meant not only that a sixth heavenly body—the Sun—would be in the line up, but that we would be able to see it. The shadows of Ganymede and Callisto would be centered on Jupiter just as Io and Europa reached mid transit.
Full phase is at six o'clock Saturday morning; we all got up about four-thirty and were outside by five. George and I carried Peggy out in her bubble stretcher. We were just in time.
It was a fine, clear summer night, light as could be, with old Jupiter blazing overhead like a balloon on fire. Io had just barely kissed the eastern edge of Jupiter—"first contact" they call it. Europa was already a bit inside the eastern edge and I had to look sharp to see it. When a moon is not in full phase it is no trouble to pick it out while it's making its transit, but at full phase it tends to blend into the background. However, both Ioand Europa are just a hair brighter than Jupiter. Besides that, they break up the pattern of Jupiter's bands and that lets you see them, too.
Well inside, but still in the eastern half—say about half way to Jupiter's center point—were the shadows of Ganymede and Callisto. I could not have told them apart, if I hadn't known that the one further east had to be Ganymede's. They were just little round black dots; three thousand miles or so isn't anything when it's plastered against Jupiter's eighty-nine thousand mile width.
Io looked a bit bigger than the shadows; Europa looked more than half again as big, about the way the Moon looks from Earth.
We felt a slight quake but it wasn't even enough to make us nervous; we were used to quakes. Besides that, about then Io"kissed" Europa. From then on, throughout the rest of the show, Io gradually slid underneath, or behind, Europa.
They crawled across the face of Jupiter; the moons fairly fast, the shadows in a slow creep. When we had been outside a little less than half an hour the two shadows kissed and started to merge. Io had slid halfway under Europa and looked like a big tumor on its side. They were almost halfway to center and the shadows were even closer.
Just before six o'clock Europa—you could no longer see Io; Europa covered it—as I was saying, Europa kissed the shadow, which by now was round, just one shadow.
Four or five minutes later the shadow had crawled up on top of Europa; they were all lined up—and I knew I was seeing the most extraordinary sight I would ever see in my life, Sun, Jupiter, and the four biggest moons all perfectly lined up.
I let out a deep breath: I don't know how long I had been holding it. "Gee whiz!" was all I could think of to say.
"I agree in general with your sentiments, Bill," Dad answered. "Molly, hadn't we better get Peggy inside? I'm afraid she is getting cold."
"Yes," agreed Molly. "I know I am, for one."
"I'm going down to the lake now," I said. The biggest tide of record was expected, of course. While the lake was too small to show much tide, I had made a mark the day before and I hoped to be able to measure it.
"Don't get lost in the dark," Dad called out. I didn't answer him. A silly remark doesn't require an answer.
I had gotten past the road and maybe a quarter of a mile beyond when it hit.
It knocked me flat on my face, the heaviest shake I had ever felt in my life. I've felt heavy quakes in California; they weren't a patch on this one. I lay face down for a long moment, digging into the rock with my finger nails and trying to get it to hold still.
The seasick roll kept up and kept up and kept up, and with it the noise—a deep bass rumble, deeper than thunder and more terrifying.
A rock rolled up against me and nipped my side. I got to my feet and managed to stay there. The ground was still swaying and the rumble kept on. I headed for the house, running—like dancing over shifting ice. I fell down twice and got up again.
The front end of the house was all caved in. The roof slanted down at a crazy angle. "George!" I yelled. "Molly! Where are you?"
George heard me and straightened up. He was on the other side of the house and now I saw him over the collapsed roof. He didn't say anything. I rushed around to where he stood. "Are you all right?" I demanded.
"Help me get Molly out—" he gasped.
I found out later that George had gone inside with Molly and Peggy, had helped get Peg out of the stretcher and back into her room, and then had gone outside, leaving Molly to get breakfast. The quake had hit while he was returning from the barn. But we didn't have time then to talk it over; we dug—moving slabs with our bare hands that had taken four Scouts, working together, to lay. George kept crying, "Molly! Molly! Where are you?"
She was lying on the floor beside the stone work bench that was penned in by the roof. We heaved it off her; George scrambled over the rubble and reached her. "Molly! Molly darling!"
She opened her eyes. "George!"
"Are you all right?"
"What happened?"
"Quake. Are you all right? Are you hurt?"
She sat up, made a face as if something hurt her, and said, "I think I— George! Where s Peggy? Get Peggy!"
Peggy's room was still upright; the reinforcements had held while the rest of the house had gone down around it. George insisted on moving Molly out into the open first, then we tackled the slabs that kept us from getting at the air lock to Peggy's room.
The outer door of the air lock was burst out of its gaskets and stood open, the wrong way. It was black inside the lock; Jupiter light didn't reach inside. I couldn't see what I was doing but when I pushed on the inner door it wouldn't give. "Can't budge it," I told Dad. "Get a light."
"Probably still held by air pressure. Call out to Peggy to get in the stretcher and we'll bleed it."
"I need a light," I repeated.
"I haven't got a light."
"Didn't you have one with you?" I had had one; we always carried torches, outdoors in dark phase, but I had dropped mine when the quake hit. I didn't know where it was.
Dad thought about it, then climbed over the slabs. He was back in a moment. "I found it between here and the barn. I must have dropped it." He shined it on the inner door and we looked over the situation.
"It looks bad," Dad said softly. "Explosive decompression." There was a gap you could poke your fingers through between the top of the door and the frame; the door wasn't pressure held, it was jammed.
Dad called out, "Peggy! Oh, Peggy, darling—can you hear me?"
No answer. "Take the light, Bill—and stand aside." He reared back and then hit the door hard with his shoulder. It gave a bit but didn't open. He hit it again and it flew open, spilling him on his hands and knees. He scrambled up as I shined the light in past him.
Peggy lay half in and half out of bed, as if she had been trying to get up when she passed out. Her head hung down and a trickle of blood was dripping from her mouth on to the floor.
Molly had come in right behind us; she and Dad got Peggy into the stretcher and Dad brought the pressure up. She was alive; she gasped and choked and sprayed blood over us while we were trying to help her. Then she cried. She seemed to quiet down and go to sleep —or maybe fainted again—after we got her into the bubble.