Here’s what you need to know to start your day.

It’s Thursday, Jan. 30, 2020. Let’s start here.

1. Questions and witnesses

A new phase of the Senate impeachment trial began on Wednesday with senators taking turns posing questions to House impeachment managers and President Donald Trump’s legal team, before they’re expected to consider a motion on Friday to allow witnesses to testify.

As Democrats try to court at least four Republican senators to support hearing new testimony, ABC News contributor and former Sen. Heidi Heitkamp (D-N.D.) tells “Start Here” she thinks it’s “highly unlikely we’re going to see witnesses.”

“They’re up against an artificial timetable with the State of the Union” she says. “The president does not want to walk through the House of Representatives under trial. He wants to walk in, kind of taking a victory lap.”

2. Bernie takes all?

As the Iowa caucuses near, the latest polls in the early voting states show Sen. Bernie Sanders (I-Vt.) gaining momentum in the Democratic primary race.

“People are I think in the Democratic Party waking up to the fact that Bernie Sanders is not just a possible threat, he is a very realistic threat for the nomination,” ABC News Political Director Rick Klein says. “He could win this thing and it could start in Iowa and New Hampshire.”

3. FYI on TBI

After initially saying there were no injuries following Iran’s Jan. 8 missile attack on a military base in western Iraq, the Pentagon now says 50 American military service members suffered traumatic brain injuries.

The president last week appeared to brush off the traumatic brain and concussion-like injuries sustained by U.S. service members: “I heard that they had headaches, and a couple of other things. But I would say, and I can report it is not very serious.”

ABC News Chief Global Affairs Correspondent Martha Raddatz tells the podcast there’s a stigma with brain injuries and veterans organizations were outraged by the president’s comments, “They’re called invisible wounds because with someone who has lost a limb, people immediately realize they’ve been in a terrible situation. If you’re walking around with a brain injury. Sometimes people really don’t know.”

“Start Here,” ABC News’ flagship podcast, offers a straightforward look at the day’s top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, iHeartRadio, Spotify, Stitcher, TuneIn or the ABC News app. Follow @StartHereABC on Twitter, Facebook and Instagram for exclusive content and show updates.

Elsewhere:

‘Slashed in the face’: A mother has been slashed in the face with a knife after her child threw up on a public bus and another passenger became so enraged that she followed the mother and attacked her.

‘Never committed a violent act’: A Michigan man serving a 60-year prison sentence for selling marijuana to an informant is taking a second chance to ask for clemency from the governor.

‘Bloodhounds found nothing’: The father of a missing Florida newborn was found dead in his vehicle on Wednesday, a day after he allegedly abducted the 1-week-old baby boy and fled nearly 300 miles.

‘Shot in the head’: A 1-year-old child has been shot in the head when a gun his parents were having a physical altercation over accidentally went off during the argument.

From our friends at FiveThirtyEight:

‘New batch of Iowa polls still shows a tight race’: Three new Iowa polls dropped today pointing to a still very close race between Sen. Bernie Sanders and former Vice President Joe Biden (though former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Elizabeth Warren shouldn’t be written off).

Doff your cap:

When London-based musician Tom Rosenthal’s youngest daughter Fenn wandered into his recording studio and asked if they could write a song, even the proudest father couldn’t have predicted that the adorable resulting ballad would become an instant smash hit on social media.

Rosenthal said Fenn walked in to the studio and asked if if they could do a song, and since his answer is almost always yes, he asked her what it should be about.

“Dinosaurs,” Fenn said, according to her dad.

“She just started singing about Dinosaurs. It comes out in little bits. She’ll take a break and then come back — she just needs a point in the right direction. I’ll ask her, ‘what might happen next?’ And the words just come straight from her head. I had no idea she knew about dinosaurs, but I know her sister tells her stuff, and she’s a bright little kid.”