PHOENIX, Ariz - (AP) - Jared Loughner, head shaved, a cut on his righttemple and his hands cuffed, stared vacantly at a packed courtroomMonday and sat down. His attorney, who defended "Unabomber" TedKaczynski, whispered to him.

It was the nation's first look at the 22-year-old loner accusedof trying to assassinate Rep. Gabrielle Giffords.

The three-term Democrat lay about a 100 miles away in a Tucsonintensive care unit, gravely wounded after being shot through thehead but able to give a thumbs-up sign that doctors found as areason to hope.

Loughner seemed impassive and at one point stood at a lectern inhis beige prison jumpsuit. A U.S. marshal stood guard nearby.

The judge asked if he understood that he could get life inprison - or the death penalty - for killing federal Judge JohnRoll, one of six who died in the shooting rampage at Giffords'outdoor meeting with constituents Saturday in Tucson.

"Yes," he said. His newly appointed lawyer, Judy Clarke, stoodbeside him as the judge ordered Loughner held without bail.

Throngs of reporters and television news crews lined up outsidethe federal courthouse, where the hearing was moved from Tucson.The entire federal bench there recused itself because Roll was thechief judge.

President Barack Obama will travel to Arizona on Wednesday toattend a memorial service for the victims.

Earlier in the day, the nation observed a moment of silence forthe victims, from the South Lawn of the White House and the stepsof the U.S. Capitol to legislatures beyond Arizona and the planetitself. At the International Space Station, Giffords'brother-in-law, Scott, the commanding officer, spoke over the radioas flight controllers in Houston fell silent.

"As I look out the window, I see a very beautiful planet thatseems very inviting and peaceful," he said. "Unfortunately, it isnot.

"These days, we are constantly reminded of the unspeakable actsof violence and damage we can inflict upon one another, not justwith our actions, but also with our irresponsible words," he said.

"We're better than this," he said. "We must do better."

On a frigid morning outside the White House, Obama and firstlady Michelle Obama stood side by side, each with their handsclasped, heads bowed and eyes closed. On the steps of the U.S.Capitol, congressional staff and other employees did the same.

At the Supreme Court, the justices paused for a moment ofsilence between the two cases they were hearing Monday morning. The president called for the country to come together in prayeror reflection for those killed and those fighting to recover.

"In the coming days, we're going to have a lot of time toreflect," he said. "Right now the main thing we're doing is tooffer our thoughts and prayers to those who've been impacted,making sure we're joining together and pulling together as acountry."

In total, six died and 14 were injured or wounded outside asupermarket where Giffords set up a booth to hear the concerns ofconstituents. Loughner was tackled to the ground minutes after theshooting began, authorities said. He has been silent ever since.

A Mass for all the victims was scheduled Tuesday at St. Odelia'sParish in Tucson.

Among the dead was 9-year-old Christina Taylor Green, who wasborn on the day of the Sept. 11, 2001, terrorist attacks. Herfuneral is Thursday.

It was unclear when funerals will be held for the other victims,including one of Giffords' aides.

Loughner is charged with one count of attempted assassination ofa member of Congress, two counts of killing an employee of thefederal government and two counts of attempting to kill a federalemployee. Those are federal charges.

Giffords, 40, was shot in the head at close range. She was incritical condition at Tucson's University Medical Center. Twopatients were discharged Sunday night. Seven others remainedhospitalized.

Recent CT scans showed no further swelling in the brain, butdoctors were guarded.

"We're not out of the woods yet," her neurosurgeon Dr. MichaelLemole said. "That swelling can sometimes take three days or fivedays to maximize. But every day that goes by and we don't see anincrease, we're slightly more optimistic."

Rep. Israel to change gathering locations in light of AZ tragedyArizona congresswoman shot, several killed in Tucson